
'^nata^iAMmafi 



■^W:**, g'''"'Iv U' 



<■ '^ i' 
















''k ..'^'"•-j. '!f~'t K'^S 



'^i' 



»^ 



j; -II iinmimwiiiiiii iiiirti''- -ii rt— nr jjt.tWBttiicvn.'owoni^M'ii inw<UIM>HI>liKr: 

[MT 












■' J c ■ • 


1 1 "'' 




'-.,.,/ ,1 


5 : ; V f F 




HH-^ 




n : t ■■ : 


A 


^- ^' i, ■■• 


..../f' V.-.i' 


i V H ' t ' 




j '^3^ 




n H 



t ; ' 5 C ? S i 



8 






? uh 



ImH- 



ill 




(J,iss O l (jO 



Uk^XJ^ 



i^iii:si-:NTi-;i) hy 



'Hi'- 



Ubc IRural Uext^Booft Series 

Edited by L. H. BAILEY 



THE FEEDINa OF ANIMALS 



Ubc IRural Ucxu:Booh Series 

Edited by L. H. BAILEY 

Carleton, The Small Grains. 

B. M. Duggar, Plant Physiology, with 

special reference to Plant Production. 
J. F. Duggar, Southern Field Crops. 
Gay, The Breeds of Live-Stock. 
Gay, The Principles and Practice of 

Judging Live-Stock. 
Goff, The Principles of Plant Culture, 

Revised. 
Harper, Animal Husbandry for Schools, 
Harris and Stewart, The Principles of 

Agronomy. 
Hitchcock, A Text-Book of Grasses. 
Jeffery, Text-Book of Land Drainage. 
Jordan, The Feeding of Animals. Revised. 
Livingston, Field Crop Production. 
Lyon, Fippin and Buckman, Soils — Their 

Properties and Management. 
Mann, Beginnings in Agriculture. 
Montgomery, The Corn Crops. 
Piper, Forage Plants and Their Culture. 
Warren, Elements of Agriculture. 
Warren, Farm Management. 
Wheeler, Manures and Fertilizers. 
White, Principles of Floriculture. 
Widtsoe, Principles of Irrigation Practice. 



THE 

FEEDffiG OF Al^IMALS 



BY 

WHITMAN HOWARD JORDAN 

DIRECTOR OF THE NEW YORK AGRICULTURAL 
EXPERIMENT STATION, GENEVA 



REVISED EDITION 



J^eiD gorfe 
THE MACMILLAN COMPANY 

1917 

AH nghis veseraed 



V 



Copyright, 1901 and 1917 
By the MACMILLAN COMPANY 



Set up and electrotyped June, 1901 

Reprinted September, 1903; February, 1905; October, 1906 

February, 1908; January and July, 1909; October, 1910 

February, 1912; January, 1914 

New and Revised Edition, January, 1917 



aiti 



jRSount l^lpastant PredS 

J. Horace McFarland Company 
Harrisburg, Pa. 



\ 



TABLE OF CONTENTS 

PART I. THE PRINCIPLES OF FEEDING 
CHAPTER I 

PAGES 

Introduction: Man's Relation to Animal Life . . 3-8 
The conditions and problems involved in feeding animals. 

CHAPTER II 

The Relations of Plant and Animal Life . . . 9-11 
Origin of animal foods, 1; The plant stores energy, 2; 
Plant substance a source of animal substance, 3; The 
plant a source of animal heat, 4; Food a source of motive 
power, 5. 

CHAPTER III 

The Chemical Elements Involved in Animal Nutri- 
tion 12-25 

Chemical elements involved in animal growth, 6. 
The Elements and Their Sources: Carbon, 7; Carbon in 
the air, 8; Oxygen, 9; Uses of oxygen, 10; Hydrogen, 
11; Nitrogen, 12; Supply of nitrogen, 13; Uses of 
nitrogen, 14; Argon, 15; Sulfur, 16; Phosphorus, 17; 
Chlorine, 18; Iodine, 19; Potassium, 20; Sodium, 21; 
Calcium, 22; Iron, 23. Proportions of the Elements in 
Plants and Animals: Elements in plants, 24; Elements 
in plant ash, 25; Elements in animals, 26; Ash elements 
in animals, 27; Classes of matter, 28; Combustion does 
not destroy matter, 29; Relation of combustible to 
incombustible substance, 30; Organic and inorganic 
classes, 31. 

(v) 



VI CONTENTS 

CHAPTER IV 

The Compounds of Animal Nutrition .... 26-46 
The classes of compounds, 32; Distribution of ele- 
ments, 33. Water: Measurement of water-content, 34; 
Hygroscopic water, 35; Physiological water, 36; Water 
in Uving plants, 37; Sap or plant juice, 38; Proportion 
of water in plants, 39; Effect of stage of growth on 
water-content, 40; Influence of soil moisture, 41; Supply 
of water to plants, 42; Water in feeding-stuffs, 43; Con- 
ditions affecting water-content of feeds, 44; Relation of 
water to preservation of cattle foods, 45; Water in the 
animal, 46; Variations of water-content of animal 
bodies, 47. Ash: Mineral compounds in the ash of plants 
and animals, 48; Rearrangement of ash elements during 
ignition, 49; The ash compounds of plants, 50; Varia- 
tions of plant ash, 51 ; Variations of ash due to species, 
52; The distribution of mineral compounds in the differ- 
ent parts of the plant, 53; Influence of manufacturing 
processes on the ash constitutents, 54; The mineral 
compounds of animal bodies, 55; The distribution of 
inorganic compounds in the animal body, 56; Ash ele- 
ments in the soft tissues, 57; Ash elements in the blood, 
58. 

CHAPTER V 

The Compounds of Animal Nutrition, Continued — 

The Nitrogen Compounds 47-67 

The importance of protein, 59. Protein: How protein 
is determined, 60; So-called proteins greatly unlike, 61; 
Classification of proteins, 62; The true proteins, 63; 
Ultimate composition of proteins, 64; Fa mili ar exam- 
ples of proteins, 65. Simple Proteins: The albumins, 
66; The globulins, 67; Plant globulins, 68; Animal glob- 
ulins, 69; Glutenins, 70; Alcohol-soluble proteins, 71; 
Albuminoids, 72; Histones, protamines, 73. Conjugated 
Proteins: Nucleo-proteins, , 74; Glyco-proteins, 75; 
Phospho-proteins, 76; Haemoglobin, 77; Lecitho-pro- 
teins, 78. Derived Proteins: 1. Primary Protein Derive^ 
lives: Proteins and metaproteins, 79; Coagulated pro- 



CONTENTS . vii 

teins, 80. 2. Secondary Protein Derivatives: Proteoses, pages 
peptones, 81; Important properties of the proteins, 82; 
The unhke constitution of the various proteins, 83; 
Cleavage products of the proteins, 84. Nitrogen Com- 
pounds That Are Non-Proteins: Amino-acids and 
amides, 85; Extractives, 86. 

CHAPTER VI 

The Compounds of Animal Nutrition, Concluded — 

Carbohydrates, Acids, Fats, and Oils . . . 68-86 

Elementary composition of the non-nitrogenous 
compounds, 87; Classification of non-nitrogenous com- 
pounds, 88; The carbohydrates, 89; Classification of 
carbohydrates according to structure, 90; The mono- 
saccharides or simple sugars, 91; Dextrose, 92; Levulose, 
93; Galactose, 94; The pentoses, 95; Di-saccharides, 
96; Saccharose, 97; Maltose, 98; Lactose, 99; The sugars 
as a class, 100; Other more complex poly-saccharides, 
101; The starches, 102; Glycogen, 103; The pentosans, 
104; Galactans, mannans, levulans, dextrans, 105; The 
pectin bodies, 106; Dextrin, 107; Cellulose, 108; The 
acids, 109; Fats and oils, 110; Fats or oils in grains and 
seeds. 111; Nature and kinds of fats, 112; Physical 
properties of the fats and oils, 113; Milk-fat, 114; 
Fatty acids, 115; Ether-extracts, 116; Lecithins, 117; 
Enzyms, anti-bodies, hormones, vitamines (accessories), 
118. 

CHAPTER VII 

The Digestion of Food 87-122 

Digestion vs. assimilation, 119; General changes in 
food through digestion, 120. Ferments: Definition of fer- 
ments, 121; Organized ferments, 122; Structure and 
distribution of organized ferments, 123; Conditions of 
growth of organized ferments, 124; Results of fermenta- 
tion, 125; Manner of action of ferments, 126; Bacteria in 
the digestive tract, 127; Unorganized ferments, 128; 
Enzyms and their action, 129. The Alimentary Canal: 



Vlll CONTENTS 

Parts of the alimentary canal, 130. The Mouth: Masti- 
cation, 131; The teeth, 132; The saliva, 133; Origin of 
saliva, 134; Properties and office of sahva, 135; Quan- 
tity of saliva excreted, 136. The Stomach: The rumi- 
nant stomach, 137 ; Esophageal groove, 138; The rumen, 
139; The reticulum, 140; Rumination, 141; The omasum, 
142; The abomasum, 143; The gastric juice, 144; Arti- 
ficial digestion, 145; Changes in stomach digestion, 146 
Hydrochloric acid essential in stomach digestion, 147 
The stomachs of the horse and pig, 148. The Intestines 
Form and length of intestines, 149; Food in the small 
intestine, 150; The bile, 151; Functions of bile, 152; 
The pancreatic juice, 153; The enzyms of the pan- 
creatic juice, 154; Steapsin, 155; Amylopsin, 156; 
Intestinal juices, 157; Intestinal bacteria, 158; Effects 
of intestinal fermentations, 159; Stimuli to digestion, 
160; Secretins, 161; The psychic factor, 162; Digestion of 
food as a whole, 163; Stomach digestion, 164; Digestion 
in intestines, 165; Digestive fluids act together, 166; 
Action of intestinal juices, 167; Summary of changes 
in digestion, 168. Absorption of Food: Function of 
lacteals and blood vessels in absorption, 169; Manner of 
food absorption, 170; Changes in the walls of the intes- 
tinal tract, 171; Place of maximum absorption of food, 
172. The Feces: Constituents of feces, 173; The feces 
not wholly undigested food, 174. The Relation of the Dif- 
ferent Food Compounds to the Digestive Processes: Digesti- 
bility of the proteins, 175; Digestibility of the carbo- 
hydrates, 176; Starches unHke in rate of digestibility, 
177; Digestibility of cellulose and gums, 178; Digesti- 
biHty of the fats, 179. Factors Which May Influence 
Digestion: Meaning of "digestibility," 180. 



CHAPTER VIII 

Conditions Influencing Digestion 123-137 

Palatableness, 181; Influence of quantity of ration, 
182; Effect of drying fodders, 183; Influence of the con- 
ditions and methods of preserving fodders, 184; Influ- 



CONTENTS ix 

ence of the stage of growth of the plant, 185; Influence pages 
of methods of preparation of food, 186; Wetting food, 
187; Cooking foods, 188; Influence of grinding foods, 
189; Effect of common salt, 190; Influence of frequency 
of feeding and watering animals, 191; Influence of 
season and storage, 192; Influence of the combination 
of food nutrients, 193; Influence of work, 194; Influence 
of species, breed, age, and individuality, 195; Lower 
digestibihty with horses for coarse foods, 196; Deter- 
mination of digestibility, 197; The inaccuracies of 
digestion coefficients, 198. 

CHAPTER IX 

The Distribution and Use of the Digested Food . 138-150 
The blood, 199; The blood corpuscles, 200; The blood 
plasma, 201; The heart, 202; Circulation of blood, 203; 
The lungs, 204; Object of respiration, 205; The use of 
food, 206; Nutrients are oxidized, 207; Oxidases, 208; 
Proteins not wholly oxided, 209; Rate of oxidation of 
nutrients, 210. Elimination of Wastes: Elimination of 
urea, 211; Elimination of carbon dioxid, 212; Elimina- 
tion of water, 213. The Liver: Regulation of carbo- 
hydrate use, 214. 

CHAPTER X 

The Functions of the Nutrients 151-196 

General uses of food, 215; Uses of energy, 216; Func- 
tions of water, 217. Functions of the Mineral Elements 
Relation of mineral elements to vital processes, 218 
Relation of mineral elements to animal structure, 219 
Distribution of mineral elements in animal body, 220 
Relation of mineral elements to elimination of waste 
products, 221; Relation of mineral elements to a proper 
equihbrium between the acids and bases of the animal 
body, 222; Relation of mineral elements to osmosis, 
223; Relation of mineral elements to muscular control, 
224; Relation of mineral elements to tissue development, 
225; General considerations, 226; Supply of mineral ele- 



X CONTENTS 

ments, 227; Relative efficiency of different phosphorus 
• compounds, 228. Functions of Protein: Proteins as 
tissue-formers, 229; Protein as a source of fats, 230; 
Protein as a source of energy, 231. Functions of Car- 
bohydrates: Carbohydrates the chief source of energy, 
232; Proportion of ration used as fuel, 233; Fats from 
carbohydrates, 234. Functions of the Fats and Oils: 
Fats and carbohydrates similar in function, 235. Food 
as a Source of Energy: Work performed by the animal 
organism, 236; Work requires the expenditure of energy, 
237; The animal organism does not originate energy, 
238; The nature of energy, 239; Transformations of 
energy though the use of machinery, 240; The horse a 
machine, 241; Measurement of energy, 242; Determina- 
tion of energy units in feeding-stuffs, 243; MetaboHzable 
energy, 244; Loss of food energy in feces, 245; Loss of 
food energy in urine, 246; Loss of food energy in gases, 
247; Recent determinations of metaboUzable energy, 
248; Distribution of losses of food energy, 249; Influence 
of size of ration on losses of methane, 250; Influence 
of size of ration on losses in the undigested residue, 251 ; 
Influence of individuahty on energy losses, 252; 
Estimates of metaboHzable energy on the basis of 
digestible organic matter, 253; Comparison of metaboHz- 
able energy in coarse fodders and grains, 254; Net 
energy, 255; Work of mastication, 256; Difference in 
total energy use with different rations, 257; The work of 
digestion, 258; Total energy expended in feed consump- 
tion, 259; Calculation of net energy value, 260; Net 
energy of various feeds, 261; Computing net energy 
values of feeding-stuffs, 262; Estimation of produo- 
tion values proposed by Armsby, 263. Energy Rela- 
tions. — Heat Regulation: Relation of protein to 
muscular activity, 264; Energy chiefly from carbohy- 
drates and f-ats, 265; Heat regulation, 266; Animal heat a 
secondary or waste product, 267; The critical tempera- 
ture, 268. The Nutritive Inter-Relation of the Food Com- 
pounds and the Need of Combining These in the Ration: 
Protein physiologically necessary, 269; Carbohydrates 



CONTENTS ^ xi 

physiologically economical, 270; Protein-sparers, 271; ^ageb 
Nutritive value of the gums, 272; Relative importance 
of the nitrogen compounds of feeding-stuffs, 273; Rela- 
tive 'nutritive efficiency of the true proteins, 274; A 
single amino acid a limiting factor, 275; Nutritive value 
of the gelatinoids, 276; Synthesis in the animal of phos- 
phorus-bearing proteins, 277; The function of certain 
unidentified bodies, 278; Relation of production 
values to profit from feeding animals, 279. 

CHAPTER XI 
Laws of Nutkition 197-200 

CHAPTER XII 
SouHCES OF Knowledge 201-215 

Conclusions from feeding practice, 289; Practical 
feeding experiments, 290; Inconclusiveness of ordinary 
feeding experiments, 291; Chemical and physiological 
studies, 292; More accurate methods of investigation 
than practical feeding tests, 293; Studies of food 
sources of animal fats, 294; The respiration apparatus, 
295; Determination of energy values, 296; Calculation 
of the energy value of a ration, 297; Energy value of 
digested nutrients, 298; Measurement of food com- 
bustion, 299; Respiration calorimeter, 300; Study of 
the efficiency of individual proteins, 301. 



PART II. THE PRACTICE OF FEEDING 

CHAPTER XIII 

Cattle Foods — Natural Products 219-241 

Classification of cattle foods, 302. Forage Foods: 
Classes of forage crops, 303; Green vs. dried fodders; 
conditions of drying, 304; Effect of drying fodders, 



XU CONTENTS 

305; Losses through curing fodders, 306; The harvest- ^^^^^ 
ing of forage crops, 307; Maximum ^aeld of forage crops 
at maturity, 308; Value of crops not proportional to 
yield, 309; Age decreases digestibility, 310; Maize unlike 
other grasses, 311; Alfalfa, 312. Silage: Nature of the 
changes in the silo, 313; losses in silo, 314; Corn an 
important silo crop, 315; Extent of loss in the silo, 316; 
Necessary loss in silo, 317; Financial importance of 
silo losses, 318; Ensiling vs. field-curing, 319; Crops for 
silage, 320; Construction of silo, 321; Filling the silo, 
322; Mature corn desirable for silage, 323; Cutting and 
shredding ensilage material, 324; Rate of filling silo, 
325. The Straws: 326. Roots and Tubers: 327% Grains 
and Seeds: 328. Storage of grain, 329. 

CHAPTER XrV 

Cattle Foods — Commercial Feeding-Stuffs . . . 242-271 

Classes of commercial by-product feeding-stuffs, 330; 
Wheat offals, 331; Structure of the wheat grain, 332; 
The milling of wheat, 333; Composition of miUing prod- 
ucts of wheat, 334; Milling processes compared, 335; 
Screenings, 336; Residues from breakfast foods, 337; 
The oat grain, oat hulls, 338; Oat cUppings, 339; Barley 
feed, 340; Hominy feed, 341; Brewers' grains; malt- 
sprouts, 342; Residues from starch and glucose manu- 
facture, 343; Structure of the maize kernel, 344; Manu- 
facture of starch, 345; Residues from the manufacture of 
beet-sugar, 346; The oil meals in general, 347; Methods 
of extracting oils, 348; Cottonseed meal, 349; Cotton- 
seed hulls, 350; Extraction of oil from the cottonseed 
kernels, 351; Composition of cottonseed oil by-prod- 
ucts, 352; Linseed oil (oil meal), 353; Extraction of 
hnseed oil, 354; Old process vs. new process Hnseed 
meal, 355. Chemical Distinctions in Cattle Foods: 
Coarse foods vs. grains and grain products, 356; Classi- 
fication of feeds according to the proportion of nutrients, 
357; Misleading terms for feeding-stuffs, 358; Classi- 
fication of feeding-stuffs, 359. Foods of Animal Origin: 



CONTENTS xiii 

360. Milk, 361; Milk of several breeds, 362; Dairy p*°=8 
by-products, 363; Slaughter-house and other animal 
refuses, 364. 

CHAPTER XV 

The Production of Cattle Foods 272-280 

Adaptability of crops to environment, 365; New vs. 
old species of plants, 366; AdaptabiHty of crops to kind 
of animal production, 367; Productive capacity of 
crops, 368; Crops of high productivity, 369; Home sup- 
ply of protein, 370; Legumes and fertility, 371. Soiling- 
crops: SoiUng-crops a necessity, 372; Conditions favora- 
ble to soiling, 373; The economy of soihng-crops, 
374; Selection of soiling-crops, 375; Soihng-crop area 
and rotations, 376. 

CHAPTER XVI 

The Valuation of Feeding-Stuffs 281-291 

Basis of assigning values to feeding-stuffs, 377; Com- 
mercial values of feeding-stuffs, 378. Valuation of feeds 
by method of least squares, 379; Physiological values, 
380; Energy values as a basis of valuation, 381; Con- 
ditions involved in the selection of feeding-stuffs, 382; 
Digestibihty as a basis for selecting feeding-stuffs, 
383; Values based on digestibihty, 384; Digestibihty 
of various feeds, 385; Valuations based on protein con- 
tent, 386; Feed values based on feeding experiments, 
387; The verdict of the cow, 388. 

CHAPTER XVII 

The Selection and Compounding of Rations . ■ . 292-306 
Palatableness as a factor in • feeding animals, 389; 
Adaptation of rations, 390; Physiological require- 
ments, 391; Feeding standards, 392; Nutritive ratio, 
393; Calculating a ration, 394; Calculation of digestible 
nutrients, 395; Digestible nutrients in a given ration, 
396; Correcting an insufficient ration, 39-7; Relation 



XIV CONTENTS 

of ration to size of animal, 398; The protein supply, ^^°^® 
399; Earlier protein standards revised, 400; Presence of 
growth-promoting bodies, 401; Influence of ration on 
quality of product, 402; Home supply of feeding-stuffs 
to be considered, 403; Selection of a ration largely a 
business matter, 404. 

CHAPTER XVIII 

Maintenance Rations . . 307-318 

Definition of maintenance ration, 405; Character of 
maintenance ration, 406; Uses of production ration, 407; 
Maintenance ration easily provided, 408. Maintenance 
Ration for Bovines: Various investigations concerning 
maintenance needs, 409; Fasting kataboUsm as a 
measure of maintenance needs, 410; Distribution of 
maintenance energy, 411; Use of nutrients in fasting 
metabolism, 412; Computation of maintenance needs, 
413; Maintenance rations for bovines, 414. Maintenance 
Food for Horses: Studies of the maintenance needs of the 
horse, 415; Maintenance rations for horses, 416; Main- 
tenance food for sheep, 417. 

CHAPTER XIX 
Milk Production 319-345 

Composition of cow's milk, 418; Milk secretion, 
419; Food sources of milk proteins, 420; Food sources of 
milk-fats, 421; The rate of formation of milk sohds, 
422; Uses of nutrients in milk production, 423; Pro- 
tein requirements for milk production, 424; Relative 
importance of protein overstated, 425. Feeding 
Standards for Dairy Cows: Thaer's hay values, 426; 
Grouven's milk-feeding standards, 427; Wolff's feeding 
standard, 428; Kiihn's feeding standard, 429; The 
Wolff-Lehmann feeding standards, 430; American feed- 
ing standards, 431; Woll's standard, 432; Standards 
for milk production based on elaborate American feed- 
ing experiments, 433; Requirements of certain feeding 
standards for dairy cows, 434; Calculation of rations 



CONTENTS , XV 

for dairy cows, 435; Suggested practical rations for p^geb 
dairy cows, 436; The sources of commercial protein for 
milk production; the home supply, 437; Commercial 
proteins, 438; No single protein food essential, 439. 
Tlfie Relation of Food to the Composition and Quality 
of Milk: Efifect of food on the proportion of milk solids, 
440; Efifect of food on the constitution of milk solids, 441 ; 
Influence of food on the milk-fats, 442 ; Efifect of food on 
the flavors of milk and its products, 443. 

CHAPTER XX 

Feeding Growing Animals 346-361 

The requirements for growth, 444; Food freely appro- 
priated by growing animal, 445; Influence of kind of 
food on kind of gro\vth, 446; Estimated energy require- 
ments for one pound of gain in weight by growing 
cattle and sheep, 447 ; Milk for young animals, 448. The 
Feeding of Calves: Skimmed milk as a substitute for 
whole milk in feeding calves, 449; Calf rations without 
milk products, 450. The Feeding of Lambs: Feeding 
ewes with lamb, 451; Grain foods accessible to lambs, 
452; Standards for growing sheep, 453. Feeding Colts: 
Food as related to quahty of the "horse, 454; Feeding 
the colt through the dam, 455; Rations for the colt 
before weaning, 456; Oats as horse feed, 457; Rations 
for growing colts, 458. 

CHAPTER XXI 

Feeding Animals for the Production of Meat . 362-386 

Beef Production: Nature of the growth with beef 
production, 459; Rate of increase of fattening animals, 
460; The food needs of the fattening steer, 461 ; Scientific 
experiments with fattening animals, 462 ; Practical 
feeding experiments in fattening animals, 463; German 
fattening for bovine's rations excessive, 464; The selec- 
tion of a fattening-ration, 465; Suggested rations for 
fattening steers, 466. Mutton Production: Place of 
sheep on the farm, 467; The nature and extent of the 



Xyi CONTENTS 

growth in fattening sheep, 468; Food needs of fatten- ^^°=^ 
ing sheep, 469; Quantity of nutrients for fattening 
sheep, 470; The selection of a ration for sheep, 471. 
Pork Production: Changes in pork production, 472; 
Character of the growth in pork production, 473; Food 
requirements for pork production, 474; Pigs unwisely- 
fed, 475; Point of view in feeding pigs, 476; Influence of 
ration on the development of swine, 477; Dairy wastes 
as food for pigs, 478; Protein foods other than milk 
products for swine, 479; Forage crops for swine, 480. 

CHAPTER XXII 

Feeding Working Animals 387-398 

The horse a machine, 481 ; The work performed by a 
horse, 482; Influence of conditions on the food expendi- 
ture for a unit of work, 483 ; The food requirements of a 
working horse, 484; Estimate of work ration for the 
horse based on energy relations, 485; Source of the ration 
for working horses, 486; Nutritive ratio for working 
horses, 487; Oats for working horses, 488; Suggested 
rations for working horses, 489. 

CHAPTER XXIII 

The Feeding op Poultry. By Wilham P. Wheeler . . 399-417 
Food needs of birds intensive, 490; Kinds of foods for 
poultry, 491; Incidental effects of the food with laying 
hens, 492; Digestive apparatus of birds, 493; Constitu- 
ents of the body of the hen, 494; Composition of eggs, 
495; Necessity for considering the water-supply, 496 
Efficiency of protein from animal sources for fowl, 497 
Ash constituents important for egg production, 498 
Common salt a necessity for fowls, 499; Supply of grit 
for fowls, 500; Feeding standards for fowls, 501; Main- 
tenance rations for fowls, 502; Rations for laying hens, 
503; Rations for young birds, 504; Adaptability of vari- 
ous foods for fowls, 505; Knowledge of the nutrition of 
fowls hmited, 506. 



CONTENTS , Xvii 

CHAPTER XXIV 

PAGE3 

The Relation of Food to Production .... 418-424 
Food unit defined, 507; The unit of production, 508; 
Factors involved in food economics, 509; Relation of 
food to production with various species, 510. 

CHAPTER XXV 

General Management 425-434 

Factors in general management of animals, 511; The 
selection of cows, 512; The general-purpose cow, 513; 
The selection of animals for meat production, 514; 
Relation of age to meat production, 515; Manipulation 
of the ration, 516; Quantity of the ration, 517; Environ- 
ment and treatment of animals, 518; Cruelty to ani- 
mals, 519. 

Appendix 435-463 

1. Average composition of American feeding-stuffs . 435 

2. Average coefficients of digestion 441 

3. Computation of energ;y'-production values . 448 

4. Food standards for milk production as developed by 

Haecker, Savage, and Eckles 455 

5. Feeding standards 457 

6. Fertihzing Constituents of American Feeding-Stuffs. 460 



PART I 
THE PRINCIPLES OF FEEDING 



% 



THE FEEDING OF ANIMALS 



CHAPTER I 

INTRODUCTION: MAN'S RELATION TO 
ANIMAL LIFE 

There was a time somewhere in the dim past when 
the beast of the field knew no master. The only obe- 
dience which he rendered to a superior power was an 
unconscious submission to Nature's stern forces. He 
wandered forth at will to find in the untilled pastures 
such food as the wild herbage afforded, and, unre- 
strained, he sought a place of rest in the tangled thicket. 
He knew no refuge from the winter's cold and storm 
but some sheltered nook or forest recess to which his 
brute intelligence guided him, and he was his own defense 
against the dangers which beset him. 

Man had not come to be a controlling factor in the 
development of the various forms of animal life. If the 
brute knew him at all, it was as the huntsman, as an 
enemy, but not as a superior to whom must be paid a 
tribute of service or of food and clothing. The wild 
ox and horse possessed those characteristics which best 
fitted them to cope with the untoward conditions of 
their environment; but there had not yet appeared those 
specialized capacities of growth, draft, speed, or pro- 
duction which now render these animals so very valuable 
for the service and sustenance of the human family. 

The qualities developed were those demanded by the 

(3) 



4 THE FEEDING OF ANIMALS 

necessities of existence without reference to utility as 
measured by the needs of a higher form of life. The fiber 
of the body must possess endurance, and it mattered 
little whether or not the muscle could furnish a juicy 
steak. The brute mother must defend her young and 
supply it with milk, and this being accomplished, her 
maternal functions ceased. She was neither so endowed 
that she could open the fountains of her life to feed gen- 
erously a not too grateful master, nor so submissive 
that she would. The wild horse must be fleet and endur- 
ing that he might escape the enemy, but not that he 
might bear heavy burdens or win a contest in the pre- 
scribed form of the race-track. ^ 

In the lapse of centuries there have been many changes 
in the relation of man to the animal creation. Bird 
and beast in various forms have come to minister to 
man*s wants, and in their present domesticated condi- 
tion are, in their turn, utterly dependent upon him for 
the food and shelter which are necessary to their physical 
welfare, or even existence. It is not too much to assert 
that the domestic animal, in the artificial environment 
imposed upon it, is entirely at man's mercy, even in 
the development of those attributes and characteris- 
tics which otherwise would be determined by the demands 
of an unaided warfare with nature. The juicy sirloin of 
the shorthorn, the almost abnormal milk glands of the 
champion butter cow, the delicate fiber of merino wool, 
and the marvelous speed of the modern race-horse are 
evidences of man's skill in recasting natural types into 
forms of greater usefulness to him. From the animal 
of nature, under the direction of a higher intelligence, 
has proceeded the animal of civilization, an organism 
obedient to the environment which has been created for it. 



INTRODUCTION ^ 5 

This interdependence of man and the lower orders 
of Hfe has a vast economic significance. A large part 
of human activity is devoted to the production and 
transportation of food for animals and to the traffic in 
the products of the dairy, slaughter-house, and sheep- 
fold, and to their utilization in various ways. The pros- 
perity of every farm is maintained to a greater or less 
extent by feeding domestic animals, and our railroads, 
our markets, in fact, nearly all our important business 
enterprises, are more or less dependent upon the extent 
and prosperity of animal husbandry. 

THE CONDITIONS AND PROBLEMS INVOLVED IN 
FEEDING ANIMALS 

The first and simplest form of animal husbandry is 
that which was practised by the nomad. His flocks 
and herds subsisted wholly by grazing and were moved 
from place to place according to the supply of forage 
afforded by different localities. No shelter was pro- 
vided for the animals and no food was stored for their 
use. The only intelligence or special knowledge that 
was brought to bear upon the business of the herdsman 
was a familiarity with the traditions and superstitions 
touching the care of cattle and the acquaintance which 
a roving life would give with the pastures furnishing 
the most abundant and sweetest wild grasses during the 
various seasons of the year. There was not then even 
a dim promise of the modern traffic in meats or of the 
fine art of dairying as we now know it. As man began to 
give up this wandering life, erect permanent dwellings, 
and confine his ownership of land to definite limits, he 
acquired the art of tillage, not only that he might have 



6 THE FEEDING OF ANIMALS 

food for his family but also for his cattle. He then began 
to store fodder in stacks, and later in barns, to meet the 
demands of the inclement portions of the year. 

For centuries, however, grazing was the chief depen- 
dence for securing the production of meat and milk because 
the foods supplied during the cold season were not in 
such abundance or so nutritious as to sustain continu- 
ous growth or milk secretion. Even within the remem- 
brance of men now living, live-stock was not expected 
to produce an increase during the winter months but was 
simply maintained from autumn until spring in order 
that profits might be realized from summer pasturage. 
Formerly the demands of the market were much simpler 
than they are now. Butter and cheese were produced 
almost wholly from summer dairying, and no such variety 
of fresh meats was offered to consumers during the entire 
year as is now the case. But great changes have occurred 
during the last fifty years, more especially during the past 
twenty-five. First of all, we have a modern type of animal, 
greatly unlike that of previous times. The ideal dairy 
cow of today is a high-pressure milk-machine extremely 
sensitive to her environment and demanding a degree of 
care in management and feeding, if she is to do her safe 
maximum work, which was not necessary with coarser 
and less delicate organisms. Every successful dairyman 
must now provide proper winter quarters for his herd 
and throughout the entire year must supply rations 
that will support continuous, generous production. He 
must do this, too, by the use of a greater variety of 
foods than was formerly available. Not only has the 
number of useful forage crops greatly increased, but the 
average farmer no longer produces all the food which his 
animals consume. He now buys numerous kinds of com- 



INTRODUCTION 7 

mercial feeding-stuffs. These purchased materials are 
not wholly the cereal grains whose value through long 
experience has come to be measured by certain prac- 
tical standards, but they consist in part of compara- 
tively new by-products from the manufacture of oils, 
starch, and human food preparations — feeding-stuffs 
which differ greatly in their nutritive properties. Besides 
all these changes, animal husbandry is now called upon 
as never before to feed the prosperous part of humanity 
with high-class products having special qualities of 
texture and flavor that depend to some extent upon 
feeding. Certainly the conditions and problems to be 
met in this branch of human industry have grown more 
and more complex. 

We must add to this the fact that, as is true with 
every department of man's activity, science has laid 
her hands upon the business of the farmer and has forced 
him into a new range of thought and practice. This 
influx of knowledge has greatly influenced the require- 
ments for meeting a sharpened competition and has 
rendered it imperative for the practitioner to bring to 
bear upon a great variety of agricultural problems a 
clear understanding of fundamental facts and principles. 

The feeding of animals involves many difficult ques- 
tions. These begin with the production of forage and 
grain crops where it is necessary to discover what ones 
will yield the largest food-values to a unit of expendi- 
ture. Economy demands that the several feeding-stuffs 
which are at command shall be so combined that there 
shall be no waste of material or energy. With several 
considerations in view, a decision must be reached as to 
the most profitable commercial foods to purchase when 
the number is large and the range of prices is wide. The 



8 THE FEEDING OF ANIMALS 

influence of the various foods upon the quality of the 
product, especially dairy products, has in recent years 
become an important matter. These and related problems 
confront the stockman and dairyman, and they demand 
for their wise solution more than what is ordinarily 
designated as practical experience. The investigator 
who shall successfully inquire into these matters must 
possess scientific qualifications of a high order; and the 
practical man, who, in a business way, conforms his 
methods to the highest standard which scientific research 
has already made possible must be familiar with the 
knowledge fundamental to the feeder's art. 



i 



CHAPTER II 
THE RELATIONS OF PLANT AND ANIMAL LIFE 

Animal nutrition has an intimate relation to plant 
growth. The farmer producing meat and milk should 
understand the relation which animal life sustains to 
plant life in order that he may so direct plant production 
as to best serve his purposes in feeding whatever class of 
animals he utilizes. The efficiency of the various plant 
products in sustaining animal life is to him a matter of 
great importance. 

1. Origin of animal foods. — The compounds which 
together constitute animal foods have their origin in plant 
life. For this reason, a study of the fundamental facts 
of animal nutrition begins with the plant. It is in the 
plant that the simple compounds derived from the soil 
and air are utilized for the production of the more highly 
complex compounds which are used for the growth of 
the animal body and for the maintenance of its 
activities. 

As soon as the young rootlets from a germinating seed 
come in contact with the soil and the first leaves reach the 
air, assimilative growth begins and continues, as for 
instance, in the wheat plant until the stalk of grain has 
reached its full height and has attained the ultimate 
object of its existence in the production of seed. Certain 
agricultural plants have the capacity of producing not 
less than 10,000 pounds an acre in a single year of plant 
substance which may serve as food for animals. 

(9) 



10 THE FEEDING OF ANIMALS 

2. The plant stores energy. — Plant life both synthesizes 
simpler compounds into complex organic substance and 
stores energy. We get evidence of this fact when wood 
is utilized as fuel for the production of heat, heat being 
one form of energy. Scientific investigation has traced 
the source of this heat to the chemical energy of the sun's 
rays, w^hich becomes stored in the plant. Combustion 
of the plant tissue liberates this energy in another form. 
Not only does this energy become available as heat, but 
it is also available for a variety of uses in the animal 
body. (See Pars. 206, 207.) 

3. Plant substance a source of animal substance. — 
The animal body, outside of the water which it con- 
tains, has its immediate origin in the food which the 
animal consumes. The mass of bone and flesh which 
make up the body of the immense bullock is derived from 
the plant substance which, in other combinations, was 
collected from the soil and air. The animal eats his 
daily ration and makes his daily gain of tissue. If food 
is withdrawn, his body wastes and dies. If his food varies 
in amount, his growth is somewhat proportional to the 
quantity eaten. It is self-evident that the bones, blood, 
and flesh of an animal are derived from what he eats. 

4. The plant a source of animal heat. — The plant not 
only supplies building-material for the animal body, but 
is the source of the heat w^ith which the animal organ- 
ism is kept warm. No matter how cold the surrounding 
atmosphere, we find that when in health the temperature 
of the ox remains at about 101° F., with but small varia- 
tion. Just as we warm a room through the combustion 
of vegetable matter, such as wood, so the temperature 
of the animal is kept at the necessary heat by the com- 
bustion of his food. The combustion, in the latter case, 



PLANT AND ANIMAL LIFE H 

is not so rapid as in the former, but the changes are the 
same though more slowly carried on. 

5. Food a source of motive power. — ^Food not only 
furnishes the constructive material for the ox's body and 
maintains animal heat, but it also supplies the animal 
machine with motive power. The energy which the 
plant acquires during its time of growth, through the 
vital processes of the animal, is transformed in part 
into motion. An animal is a living mechanism, a combina- 
tion of muscles and levers which are moved not by means 
of a spontaneous internal generation of energy, but 
through a supply of energy from without, the energy 
stored by the plant. (See Pars. 236-241.) 



CHAPTER III 

THE CHEMICAL ELEMENTS INVOLVED IN 
ANIMAL NUTRITION 

It is fundamentally necessary, to an intelligent under- 
standing of the principles and economy of cattle-feeding, 
to know the kinds and sources of the materials out of 
which vegetable and animal tissues are constructed. We 
are primarily concerned with chemical elements. 

6. Chemical elements involved in animal growth. — 
Approximately eighty substances are now believed to be 
chemical elements, i. e., substances that have not been 
resolved into two or more simpler ones, and of which, so 
far as is now known, all forms of matter are composed. 
About one-fifth of these fundamental substances are 
involved in plant growth, those that occupy a prominent 
place in animal nutrition being even less in number. 
These fifteen elements are the following, some of which 
are of minor importance: carbon, oxygen, hydrogen, 
nitrogen, sulfur, phosphorus, chlorine, iodine, silicon, 
fluorine, potassium, sodium, calcium, magnesium, iron, 
and manganese. 

At ordinary temperatures, four of these, oxygen, 
hydrogen, nitrogen, and chlorine are gases and the remain- 
ing ones are solids. Carbon, oxygen, hydrogen, and 
nitrogen are constant and important ingredients of the 
atmosphere and they exist in the soil in gases as well as 
in the various combinations. The other eleven, though 
sometimes present in the air in minute quantities, are 

(12) 



THE CHEMICAL ELEMENTS 13 

found to no appreciable extent outside of plants and 
animals except as fixed compounds in water and in the 
crust of the earth. These fifteen elementary substances 
are nearly all absolutely essential to the existence of 
animal life as now constituted. From the standpoint of 
necessity, they are, therefore, nearly all of equal value; 
but, if we take into consideration the relative ease and 
abundance of the supply, certain ones are greatly more 
important than the others. 

THE ELEMENTS AND THEIR SOURCES 

7. Carbon. — ^This is a familiar substance in common 
life. Coal and charcoal consist chiefly of carbon, while 
graphite, much used in lead-pencils and diamonds, is 
pure carbon. Carbon makes up a large proportion of 
vegetable and animal tissue. This is made evident when 
vegetable and animal tissues become black through heat- 
ing to a temperature which causes them to decompose, 
leaving the carbon as a residue while the elements with 
which it was associated are driven out. The dark humus 
bodies of the soil have undergone somewhat the same 
change. 

8. Carbon in the air. — An immense quantity of carbon 
exists in the air, combined with ox;>^gen as carbon dioxid. 
The average proportion of this compound in the atmos- 
phere by weight is approximately .06 per cent. As the 
weight of a column of air over 1 inch square of the earth's 
surface is fifteen pounds, it follows that over every acre 
of land there is an average of 28.2 tons of carbon dioxid, 
or 7.7 tons of carbon. As we know that plants draw their 
supply of carbon from the atmosphere and as vegetable 
tissue is the primary source of this element to the animal. 



14 THE FEEDING OF ANIMALS 

we safely reach the conclusion that the carbon in the 
tissues of animal life was once floating in space. 

Boussingault determined the average yearly amount of 
carbon withdrawn from the air by the crops grown on a 
particular field during a period of five years to be 4,615 
pounds. A large crop of maize or alfalfa would acquire 
even more than this. Such large drafts upon the atmos- 
pheric supply of carbon raise the question whether this 
supply remains constant. Investigation has shown that 
it does. The processes of decay through oxidation of 
vegetable and animal substance on the earth's surface, 
the combustion of wood and coal as fuel and of food com- 
pounds by animal life are all returning carbon to the air 
as carbon dioxid and it would appear that a balance is 
being maintained. The round traveled in the circula- 
tion of carbon is from the air to the plant, from the plant 
to the animal, and from the animal back to the air — a 
cycle of movement that has always existed and which will 
continue so long as life exists. 

9. Oxygen. — ^This element, next to carbon, is the most 
abundant component of the vegetable and animal tissues. 
It is second to none in the importance of its relations to the 
vital processes of nearly all forms of life. We are not 
familiar with this substance by sight because it is a trans- 
parent, colorless gas. The air is over one-fifth oxygen by 
volume. More than 21,000,000 pounds of this element are 
contained in the air above a single acre of land, a quan- 
tity which remains remarkably constant and is practically 
uniform over the entire surface of the globe. Like carbon, 
it is being continuously withdrawn from the air for pur- 
poses of combustion and is, like carbon, as continuously 
returned. Water contains nearly 89 per cent of oxygen, 
and it is estimated that the crust of the earth is one-half 



THE CHEMICAL ELEMENTS 15 

oxygen. That which enters directly into the uses of animal 
life is derived chiefly from the atmosphere and water. 

10. Uses of oxygen. — ^All life, whether vegetable or 
animal, is dependent on the use of oxygen, during which 
use this element passes into fixed combinations and back 
again into the free form. The free oxygen of the air is 
used by an animal in breathing and this it returns to the 
air in part combined with carbon as carbon dioxid. On 
the other hand, the plant appropriates the carbon dioxid 
and, through synthetical processes, the carbon is built 
into the plant tissues and the oxygen, which is set free, is 
returned to the atmosphere and may be used to sustain 
the demands of animal life. Oxygen is a factor in all 
processes of decay and in many other chemical changes. 
Fire is due to its union with the elements of the fuel. It 
is the agent which maintains combustion in the furnaces 
of our industries. The energy derived from the sun's 
rays, which is stored in vegetable tissue, when the oxygen 
is torn from its union with carbon is set free when through 
combustion the oxygen is returned to its former combina- 
tion. This circulation of oxygen is effected through the 
opportunities offered by the vital processes of the plant 
and animal. (See Par. 207.) 

11. Hydrogen. — In a free state, this element is the 
lightest known gas and is found abundantly in nature 
only in combination with other elements. A minute 
proportion exists in the air which is derived from volcanic 
action and possibly from decay under certain conditions. 
When hydrogen and oxygen are combined in the forma- 
tion of water, intense heat is produced. Hydrogen con- 
stitutes about one-ninth of water by weight and it is 
found also in a large number of soil compounds. It is an 
essential constituent of vegetable and animal tissues, but 



16 THE FEEDING OF ANIMALS 

exists in these in a much smaller proportion than carbon 
or oxygen. Its source to the plant is largely water and it 
is furnished to the animal in water and other compounds. 

12. Nitrogen and its compounds have been the 
subject of much scientific investigation in their re- 
lations to agricultural practice. Like oxygen, nitrogen 
is an invisible, tasteless, and odorless gas, which, 
according to previous determinations, forms about 77 
per cent of atmospheric air by weight. The existence in 
the air of newly discovered elements, such as argon, has 
modified previous determinations. The only place in 
nature where nitrogen or its compounds exist in large 
quantities, outside of the air and in the tissues of living 
organisms, is the sodium nitrate beds which are found 
in Chile and other localities. Soil spaces contain nitrogen 
and it is taken into solution in small proportions in all 
natural waters. It is found in mineral and organic com- 
pounds in the soil, but in quantities very insignificant as 
compared with such elements as oxygen and silicon. Few 
agricultural soils contain over 3^ per cent of combined 
nitrogen. Minute quantities of its compounds, such as 
ammonium carbonate and ammonium nitrate, exist in 
the atmosphere, which are being constantly carried to the 
soil in rain-water and as constantly replaced by ammonia 
from decomposing animal and vegetable matter and by 
the products of oxidation of nitrogen through combustion 
and electrical action. Although the compounds of nitro- 
gen exist in a comparatively small proportion, they play 
a very prominent part in agriculture, both commercially 
and physiologically. The nitrogen balance of the farm is 
important both to the crop-producer and the cattle-feeder. 

13. Supply of nitrogen. — ^The available supply of 
nitrogen compounds is often dangerously near the demand. 



THE CHEMICAL ELEMENTS 17 

and sometimes below it. The large quantity found in the 
air is inert for animal uses, and is ignored by a large 
majority of plants. Much of that in the soil is also un- 
available. Its immediately useful compounds on the farm 
are constantly subject to loss through fermentations which 
the farmer can not wholly prevent and through soil losses 
which are to some extent beyond control. The sale of 
crops removes from the farm much nitrogen. The sources 
of supply to balance this outgo are the nitric acid and 
ammonia of the rainfall, the free nitrogen captured by a 
class of plants known as legumes, that which is secured 
through purchase of fertilizers and the residues of animal 
foods. These facts relate primarily to plant production, 
but they also sustain an essential relation to the main- 
tenance of animal life. 

14. Uses of nitrogen. — Physiologically, the nitrogen 
compounds of foods stand in the front rank. These com- 
pounds are necessary building-material for the funda- 
mental tissues of the animal, and are intimately related to 
prominent chemical changes which are involved in growth 
and in the maintenance of life. 

Nitrogen compounds have come to have an important 
place in commerce. It is the most costly ingredient of 
fertilizers and the value of commercial cattle foods is in 
part dependent upon their content of these compounds. 
For all these reasons, the partial control which the farmer 
might now assume over the income and outgo of nitrogen 
compounds has become an important feature of farm 
economics. (See Par. 59.) 

15. Argon. — ^Argon exists in the atmosphere to the 
extent of about nine-tenths of 1 per cent. So far as known, 
argon does not function in vegetable and animal life. 

16. Sulfur. — ^This common and familiar substance is 



18 THE FEEDING OF ANIMALS 

found in all soils and natural waters and in all the higher 
forms of animal and vegetable life. We know it as "brim- 
stone" when fused in sticks and as "flowers of sulfur** 
when in a finely divided form. Its most common com- 
mercial compounds are sulfuric acid and the sulfates of 
potassium, sodium, calcium, and magnesium. Sulfur is an 
element essential to the building up of some of the most 
important tissues of the animal body and is supplied in 
food in the form of the sulfates and in protein com- 
binations. (See Par. 64.) 

17. Phosphorus. — ^This element occupies a very impor- 
tant place in animal nutrition. It does not exist in nature 
in an uncombined form and that found in laboratories is 
produced only by chemical means, but its compounds are 
widely distributed, those in the soil being chiefly the 
phosphates of calcium, magnesium, and iron. Large 
deposits of calcium phosphate are known, from which is 
obtained the crude phosphatic rock that serves as a basis 
for the manufacture of commercial fertilizers. All feeding- 
stuffs in their natural forms contain phosphorus com- 
pounds, such as phosphates, certain fats, and organic 
nitrogen compounds. Phosphorus is a constituent of the 
flesh of animals, and, combined with lime, constitutes a 
large part of bone. (See Par. 55.) 

18. Chlorine. — ^The chief source of chlorine to animal 
life is common salt. In some form or combination it is 
essential to the nutrition of the animal. In a free state, 
at ordinary temperatures, it is a greenish colored, dis- 
agreeable gas. ^Tien combined with hydrogen, it forms 
hydrochloric acid — a compound that occupies a promi- 
nent place in the digestion of food. Any ordinary mixed 
ration contains this element in a quantity sufficient for 
the animal's needs. (See Par. 144.) 



THE CHEMICAL ELEMENTS 19 

19. Iodine. — Iodine is distributed in nature only in 
minute quantities. It is apparently absent in some plants, 
but is found in minute quantities in others. Nevertheless 
it appears to exercise important fimctions in animal life. 

20. Potassium. — ^Familiar compounds of this element 
are the potassium carbonate leached from wood-ashes, 
saleratus, and the caustic potash of the market. This 
element is found in the flesh of all animals, mostly as the 
phosphate, and is abundantly supplied for the purposes 
of nutrition in the ordinary combinations of natural 
feeding-stuffs. 

21. Sodium. — ^This is the basal element of common 
salt, a compound which is furnished to domestic animals 
in a liberal supply. This is the only sodium compound 
v/hich it is necessary to consider. Sodium plays an impor- 
tant part in the digestion of food as it is the basis of cer- 
tain bile salts and is concerned in other ways in the 
digestive processes. (See Par. 151.) 

22. Calcium. — ^The most commonly known compound 
of this element is lime, which is calcium united with 
oxj^gen. Large masses of lime-rock, or calcium carbonate, 
exist in many parts of the earth's surface. All soils con- 
tain lime compounds. Its universal presence in plant 
tissues and in the milk of all animals in most instances 
assures a sufficient supply to meet the demands of animal 
life. The growing animal makes a generous use of lime 
because, in union with the phosphoric acid, it is the chief 
building-material of the bony framework. A deficiency 
of food lime causes an abnormal development of the bony 
structure. Lime is especially important for poultry, for 
egg-shells are mostly a lime compound. (See Par. 55.) 

23. Iron. — ^The common properties of iron are familiar 
to everyone. Iron rust and iron ore are oxides of this 



20 



THE FEEDING OF ANIMALS 



element. Iron is taken up by plants and animals in small 
quantities only, but is absolutely essential to their growth 
and welfare because of its important relation to certain 
metabolic processes. (See Par. 200.) 



PROPORTIONS OF THE ELEMENTS IN PLANTS AND 

ANIMALS 

In order to reach an intelligent understanding of the 
relation of supply and demand which exists between the 
vegetable and animal kingdoms and the raw materials 
of the inorganic world, it is necessary to know the propor- 
tions in which the elements are found in living organisms. 

24. Elements in plants. — It has been estimated by a 
German scientist, Knop, that if all the species of the 
vegetable kingdom, exclusive of the fungi, were fused into 
one mass, the ultimate composition of the dry matter of 
this mixture would be the following: 

Per cent 

Carbon 45 

Oxygen 42 

Hydrogen 6.5 

Nitrogen 1.5 

Mineral compounds (ash) 5 

The composition of various single species or parts of 
a plant, such as the fruit or straw, shows considerable 
variation from these average figures: 

Table I 





Carbon 


Oxygen 


Hydrogen 


Nitrogen 


Ash 




Per cent 


Per cent 


Per cent 


Per cent 


Per cent 


Clover hay 


47.4 


37.8 


5. 


2.1 


7.7 


Wheat kernel .... 


46.1 


43.4 


5.8 


2.3 


2.4 


Wheat straw .... 


48.4 


38.9 


5.3 


.4 


7.0 


Fodder beets .... 


42.8 


43.4 


5.8 


1.7 


6.3 


Fodder-beet leaves . . 


38.1 


30.8 


5.1 


4.5 


21.5 



THE CHEMICAL ELEMENTS 



21 



Carbon constitutes a larger proportion than any other 
element of the dry substance of plants of all species. 
Oxygen stands next in order, followed by hydrogen and 
then nitrogen. It is an important fact in the economy of 
nature that those elements which, on the average, make 
up 93.5 per cent of the dry matter of plants have as their 
main source either the atmosphere or water. Only a 
small percentage of the dry matter is drawn from the 
soil, and it is this small part that sustains the most impor- 
tant economic relations to the farmer's business. 

25. Elements in plant ash. — ^The elements of the ash 
vary materially in relative quantity in different plants. 
The following table gives the proportion of the ash ele- 
ments in a number of agricultural products: 

Table II 
Ash Elements in Cereal Grains and Vegetables* 











S 


<n 




j3 


+3 








o 


*j 




w 


03 










O 




03 






5 

c3 
O 


oJ 


e3 

■s 




t3 





Potassium . 
Sodium . . 
Calcium 
Magnesium 
Iron . . . 
Phosphorus 
Svdfur . . 
Silicon . . 
Chlorine . . 



Per 
cent 
.51 
.029 
.043 
.14 
.017 
.41 
.0032 
.018 
.006 



Per 
cent 
.36 
.012 
.023 
.135 
,008 
.29 
.0044 
.014 
.013 



Per 
cent 

.46 

.039 

.08 

.134 

.026 

.35 

.022 

.57 

.029 



Per 
cent 
1.25 
.029 
.129 
.16 
.012 
.62 
.049 
.011 
.065 



Per 
cent 
1.89 
.08 
.07 
.112 
.029 
.28 
.099 
.036 
.131 



Per 
cent 
1.68 
.86 
.44 
.14 
.038 
.31 
.14 
.06 
.25 



Per 
cent 
1.93 
1.14 
.77 
.13 
.144 
.343 
.19 
.031 
.66 



Per 

cent 

2.27 

4.32 

1.40 

.63 

.38 

.74 

.45 

.35 

1.02 



Per 
cent 
2.18 
.053 
.39 
.163 
.038 
.412 
.101 
.036 
.183 



* Calculated from Wolff's "Aschen Analysen." It is realized that more modem 
methods of analysis might modify the above figures to a small ertent, but they 
are sufficiently accurate for illustration of the variable composition of the ash of 
different species. 

26. Elements in animals. — ^The proportions of the 
chemical elements of our larger animals have been deter- 



22 



THE FEEDING OF ANIMALS 



mined through analyses made of the entire bodies of 
steers and other domestic animals by Lawes and Gilbert, 
of England, and the Maine Experiment Station, in this 
country. These results, combined with our knowledge of 
the constitution of the compounds of the animal tissues, 
enable us to calculate very closely the proportion of car- 
bon and other elements in the entire body of an ox: 



Table III 



Carbon 

Oxygen 

Hydrogen 

Nitrogen 

Mineral compounds (ash) 



Fat ox 
Lawes & Gilbert 



Per cent 

63 
13.8 

9.4 

5. 

8.8 



Two steers, 2 yrs.old 
Maine Station 



Per cent 

60 
14.1 
9. 

5.8 
11.1 



A fat ox contains a much larger proportion of carbon 
than a lean one, because the fats are richer in carbon than 
any of the other compounds of the animal body. It is 
seen that plants and animals are alike in containing much 
more of carbon than of any other element, and that the 
quantities of the remaining elements stand in the same 
order of proportion in the plant and in the animal, 
oxygen being in greater proportion in the plant, and car- 
bon and nitrogen in the animal. The plant and animal 
are alike, therefore, in consisting chiefly of elements 
derived from air and water. Carbon, oxygen, and hydro- 
gen constitute from 83 to 86 per cent of the bodies of fat 
oxen. It follows that less than one-sixth of the animal is 
built from elements that have, in part, a commercial value 
for crop production. Nitrogen and certain elements in 
the ash of the plant and animal bear a market value. 



THE CHEMICAL ELEMENTS 23 

27. Ash elements in animal. — ^The proportions of the 
ash elements are shown from analyses made of the fat 
ox by Lawes and Gilbert. For comparison, the propor- 
tions of ash elements in the human body are given: 

Table IV 



Phosphorus . . , 
Calcium . . . . 
Potassium . . . 

Sodium 

Magnesium . . . 

Oxygen 

Silicon and sulfur 



Ox 



Percent 

1.53 
2.80 
.26 
.20 
.07 
3.29 
.65 



Man 



Per cent 

1.13 

2.50 

.12 

.10 

.07 

.14 



It appears that in the ash, other than oxygen, phos- 
phorus and calcium take a leading place as to quantity, 
although other elements, such as sulfur, potassium, and 
sodium are essential to animal growth, even if present in 
relatively small amounts. 

28. Classes of matter. — A common and familiar 
phenomenon is the destruction of vegetable or animal 
matter by combustion, with the result that only a small 
portion of the original material is left behind in visible 
and solid forms. Fuel, such as wood or coal, is largely 
consumed when ignited, and we have as a residue the 
ash. If we incinerate hay, com, or wheat we get a 
similar result. The gradual decomposition of exposed 
dead vegetable matter that occurs in warm weather is a 
process essentially similar to the combustion of fuel, only 
more prolonged. In view of these facts, it is customary 
to classify all the tissues of plants and animals into the 
combustible and incombustible portions, the former being 



24 



THE FEEDING OF ANIMALS 



that part of the ignited or decayed substance which dis- 
appears in the air as gases, and the latter the residue 
or ash. 

29. Combustion does not destroy matter. — It should 
be well imderstood that combustion does not involve 
a loss of matter; only a change into other forms. If we 
were to collect the gases which pass off from a stick of 
wood that is burned, consisting mostly of carbon dioxid, 
vapor of water, and certain compounds of nitrogen, we 
would find that their total weight, plus that of the ash 
residue, is even greater than that of the dry wood, because 
the carbon and the hydrogen of the wood have united 
during the combustion with an increased amount of 
oxygen. The carbon, oxygen, hydrogen, and nitrogen of 
the plant or animal tissue belong to the combustible 
portion, although small amoimts of two of these elements 
are foimd in the ash, as it is usually estimated. The 
remainder of the fifteen elements previously named is 
supposed to appear wholly in the ash, although in different 
combinations from what they exist in the plant. 

30. Relation of combustible to incombustible por- 
tions. — ^The relation in quantity of the combustible and 
incombustible parts of vegetable and animal dry matter 
is illustrated below: 



Table V 



Clover hay . 
Potato tubers 
Maize kernel 
Wheat kernel 
Body of fat ox 



Combustible 



Per cent 

92.8 

95.5 

98.3 

98. 

91.2 



Incombustible 

(ash) 



Per cent 

7.2 

4.5 

1.7 

2. 

8.8 



THE CHEMICAL ELEMENTS 25 

The significance of these facts in their relation to 
cattle-feeding is that the chemical change which we call 
combustion is one of the phenomena of animal nutrition. 
Substances which may suffer either slow or rapid oxida- 
tion outside the animal body may undergo complete or 
partial combustion in the animal; or, stated in another 
way, the part of the plant which "burns up" in the fire- 
place or crucible is the part which in general undergoes 
the same change within the animal organism in so far as 
the food is digested. 

31. Organic and inorganic classes. — ^The terms com- 
bustible and incombustible are less used, perhaps, than 
two others which represent practically the same divisions 
of plant or animal substance, viz., organic and inorganic. 
In chemical literature, the portion of a plant or animal 
which suffers combustion is called the organic, and the 
ash is known as the inorganic part. These terms were 
evidently based on the erroneous assimiption that the 
compounds which burn and break up into simpler ones 
are peculiarly those which sustain necessary and vital 
relations to life, and are formed only through the func- 
tions of living organisms. To be sure, the dry substance 
of the plant is organized chiefly by building up com- 
pounds of carbon, oxygen, hydrogen, and nitrogen, which 
suffer combustion; but compounds of sulfur, phos- 
phorus, chlorine, potassium, sodium, and calcium are 
also constant and essential constituents of the juices and 
tissues of the plant and animal. They sustain important 
relations to nutrition and growth. It is true, however, 
that the portion of a food material which is commonly 
spoken of as organic embraces those compounds that fur- 
nish practically all the energy which is utilized by animal 
life and much the larger part of the building-material. 



CHAPTER IV 
THE COMPOUNDS OF ANIMAL NUTRITION 

The animal body consists primarily of elements, but 
we ordinarily regard it as made up of compounds. These 
are groups of elements united in such fixed and con- 
stant proportions that they have as imiform properties, 
under given conditions, as the elements themselves. In 
discussing the composition and uses of cattle foods and 
the structure, composition, and functions of the animal 
as an organism, we refer chiefly to the compounds of 
carbon rather than to carbon itself. In the language of 
practice, we speak of proteins, carbohydrates, and fats. 
Commerce recognizes these compounds also. These com- 
pounds are the source of the energy that is manifested by 
animal life, and, with the ash, of nearly all the materials 
out of which animal tissues are built. 

32. The classes of compounds. — ^The known com- 
pounds that belong to life in all its forms are almost 
innumerable. These sustain a variety of relations to 
human needs, some serving as food, some as medicine, and 
some in the arts. Comparatively few of these must be 
considered in discussing the science and art of cattle- 
feeding. Moreover, the compounds which play a leading 
part in animal nutrition are designated, especially for 
practical purposes, in classes rather than singly, which 
tends to more or less looseness of expression and definition. 
For instance, the popular understanding of the term pro- 
tein doubtless is that it is a single compound. 

(26) 



COMPOUNDS OF NUTRITION ^ 27 

The same classification is used for the compounds of 
both the vegetable and animal kingdoms, which are 
divided into the following groups : 

Water, 

Ash (mineral compounds). 

Protein (nitrogenous compounds). 

Carbohydrates (and related bodies), 

Fats (or oils). 

Variously named compounds partially theoretical 
and unclassified: Enzjins, antigens hormones, 
vitamines accessories, activators. (These terms 
are in part synon^Tns.) 

Accuracy is here sacrificed to convenience. These 
class names have come to be regarded, more or less, as 
representing entities having fixed properties and func- 
tions, whereas each class contains numerous compounds 
differing widely in their characteristics and in their nutri- 
tive value and office. Moreover, these terms have a 
variable significance as used under different conditions. 
No one of them, except water, uniformly represents just 
the same mixture of compounds when applied to unlike 
substances. 

33. Distribution of elements. — It is well to gain a 
clear understanding of the relation which the fifteen 
elements previously mentioned sustain to these classes 
of substances. This relation can be shown for the five 
main classes of nutrients, but not for the imclassified or 
theoretical bodies. Just what elements enter into these 
is not known. So far as knoTVTi they do not have a con- 
structive function. The distribution of the elements can 
be seen most readily by a tabular display : 



28 



THE FEEDING OF ANIMALS 



All vegeta- 
ble or ani-< 
mal matter 



Incombustible 


Water .... (Oxygen 

\ Hydrogen 


or inorganic 
matter . . , 




'Oxygen 

Sulfur 
Chlorine 




Ash . , . . < 


Phosphorus 
Silicon. Fluorine 
Potassium 




Sodium 




Calcium 




Magnesium 
Iron 




^ Manganese 




Carbon 


Combustible 
or organic 
matter . . . 


'Protein . . . . 


Oxygen 
Hydrogen 
Nitrogen 
Sulfur (generally) 
Phosphorus (sometimes) 
.Iron (in a few instances) 




Carbohydrates 
, and fats. . . 


Carbon 
Oxygen 
Hydrogen 



The ash which, on the average, constitutes about one- 
twentieth of the plant, and never more than one-tenth 
of the animal, may contain thirteen of the fifteen ele- 
ments, while the larger proportion of living matter con- 
sists mostly of the compounds of three or four elements, 
in no case of more than six or seven. It is strikingly 
evident that the dominant elements of life, quantity 
alone considered, are those derived from the air and water. 



WATER 



Water fills a very important place in agriculture. All 
plant substance, all animal tissue, foods, and nearly all 
the material things with which man comes in contact in 
his daily life are made up of more or less water, or are 



COMPOUNDS OF XUTRITIOX 29 

associated with it. Sometimes this is very e\ddent, as 
with green plants or juicy fruits. It is not so evident 
^^-ith straw and corn meal. If, however, we submit 
almost any substance, no matter how dry it may appear, 
except, perhaps, glass and metals, to the heat of an oven 
at 212° F., we find that a material loss of weight occurs; 
and if we so arrange that whatever is driven off is first 
drawn through some substance that entirely absorbs the 
water which has been vaporized, we learn that the decrease 
in weight is nearly all accounted for by the water thus 
collected. 

34. Measurement of water-content — ^This suggests 
to us the chemist's way of determining the proportion of 
water which any particular material contains. He weighs 
out a certain amount of the substance and then keeps it 
in an oven at 212° F. for five hours perhaps, after which it 
is re-weighed. The difference in the two weights, or the 
loss, is assumed to be aU water, and the percentage in the 
original substance is easily calculated. That portion of 
the material which is left behind after the water is evap- 
orated is called the dry substance. 

35. Hygroscopic water. — ^\Vater is associated with 
plant and animal substances and tissues in two ways, 
hygroscopically and physiologically. It is easy to illus- 
trate the former way. If an ounce of com meal were to 
be dried in an oven as described, it would, as stated, lose 
in weight. If it were subsequently allowed to remain 
exposed in the open air in a barn or out-of-doors, it would 
regain part or aU of its original weight. The loss would 
be due to water driven away by heat, and the gain to 
water absorbed from the atmosphere, which we caU 
hygroscopic moisture. 

AU solids attract moisture up to a certain proportion 



30 THE FEEDING OF ANIMALS 

which varies with the substance and with the conditions 
that prevail. The surfaces of the particles of matter are 
ordinarily covered with a thin film of water, which is 
thicker on a cold, wet day than on a warm, dry day, and 
so the same quantity of hay or grain weighs less at one 
time than at another, because the percentage of hygro- 
scopic water varies. An equilibrium will always be estab- 
lished between the attraction of a substance for moisture 
and the tension of the vapor of water in the surrounding 
air, which accounts for the effect of temperature and of 
the degree to which the air is saturated with water- vapor. 
As all substances do not have the same attraction for 
moisture, therefore, under similar atmospheric conditions, 
one feeding-stuff may retain more water than another. 

36. Physiological water. — ^Water that is held physio- 
logically is that which is a constant and essential part of 
living organisms, in which relation it is necessary to life 
and performs certain important functions. These func- 
tions are of three kinds: (1) The presence of water in the 
tissues of plants and animals gives them more or less firm- 
ness or rigidity combined with elasticity; (2) water acts 
as a food-solvent; (3) water is the great carrier of food 
materials and of waste products from one part to another 
of the vegetable or animal organism. 

37. Water in living plants. — ^Water constitutes a large 
proportion of the weight of all living plants, especially 
during the period of active growth. The cured hay weighs 
much less than did the green grass when it was cut, and 
this loss in weight is due almost wholly to evaporation of 
water from the tissues of the plant under the influence of 
the sun and wind. This water, which is contained in the 
cells, tubes, and intercellular spaces of the stalk or leaf, is 
pure water and has no more physiological value for the 



COMPOUNDS OF NUTRITION , 31 

animal than water from any other source excepting that 
it is pure and is not subject to the contamination which 
sometimes occurs in streams and w^ells. There is no such 
thing as the so-called natural water of plants, which has 
a peculiar nutritive value or function. 

38. Sap or plant juice. — ^Vegetation water should be 
distinguished from sap or plant juice. Sap is more than 
Water; it is water holding in solution certain substances 
such as sugars and mineral salts. When the plant is 
dried, these soluble compounds do not pass off, but remain 
behind as part of the dry matter. 

39. Proportion of water in plants. — ^The proportion of 
water in plants varies greatly in different species, and in 
the same species according to the stage of growth or the 
surrounding conditions. These facts have more impor- 
tance than is generally recognized, because the food 
value of vegetable substances is largely determined by the 
proportion of dry matter. It is always necessary to know 
the percentage of water in a green plant before we can 
estimate its worth for feeding purposes. 

The variations in water-content of the living tissues of 
different species of plants or parts of plants are well illus- 
trated by the following average figures: (See Pars. 304- 
303.) 

Table VI. Water in Green Plants Percent 

Pasture grass (mixed) 80. 

Timothy grass 61.6 

Oats (fodder) 62.2 

Rye (fodder) 76.6 

Sorghum (fodder) 79.4 

Fodder corn, dent, kernels glazed 73.4 

. Red. clover 70.8 

Alfalfa 71.8 

Horse-bean 84.2 

Potatoes (tubers) 78.9 

Turnips 90.5 



32 THE FEEDING OF ANIMALS 

40. Effect of stage of growth on water-content. — 

Immature plants contain more water than older or mature 
ones. Young pasture grass is more largely water than the 
same plants would be after the seed is formed. This fact 
is consistent with the very rapid transference of building- 
material during the active stages of growth. Analyses of 
samples of timothy grass cut at the Maine State College, 
in 1879, and at the Pennsylvania State College, in 1881, 
show the marked influence of the stage of growth on 
the water-content of the living plant : 

Table VII. Timothy 
Maine State College ^of'wa\ef 

Nearly headed out 78.7 

In full blossom 71.9 

Out of blossom 65.2 

Nearly ripe 63.3 

Pennsylvania State College Percentage of water 

Highly No 

manured manure 

Cut June 6, heads just appearing . , . 79.7 76.5 

Cut June 23, just beginning to bloom . 69.7 69.1 

Cut July 5, somewhat past full bloom . 61.4 60. 

What is true of timothy is probably true of all forage 
crops in the perfectly fresh state. We have here an expla- 
nation of the difficulty of curing early cut grass. When 
the farmer begins haying, at least two drying days are 
needed in order to secure a product that will not ferment 
in the mow, while later in the season, grass cut in the 
morning may be safely stored in the mow before night. 
At the Maine State College, in 1880, immature timothy 
grass lost 56.7 per cent weight in curing and the ripe 
grass only 12.9 per cent. The extreme succulence of 
immature corn and other crops previous to the formation 
of seed is a fact which the dairyman who feeds soiling- 



COMPOUNDS OF NUTRITION . 33 

crops must consider if he would uniformly maintain a 
ration up to the desired standard. 

41. Influence of soil moisture. — ^The proportion of 
water in plants is influenced also by the lack or excess of 
soil moisture. The soil and not the atmosphere is the 
source of supply of vegetation water, which, taken up by 
the roots, traverses the plant and passes into the atmos- 
phere through the leaves. If the supply is abundant, the 
tissues are constantly fully charged, but if, by reason of 
drought, the soil becomes very dry, the outgo of water 
by evaporation may exceed the income. During a drought 
vegetation water often falls below the normal, or below 
what is necessary to maintain the tissues in their usual 
condition of rigidity or to perform fully their physio- 
logical functions. 

42. Supply of water to plants. — ^This leads to the 
observation that the water in a growing plant is that 
which is in transit from the soil to the air. This liquid 
stream enters the plant with its load of building-materials, 
takes into solution the compounds elaborated in the 
leaves and aids in transporting them to the points of 
rapid growi:h, finally passing into the air from the sur- 
face of the foliage. Throughout the entire growing sea- 
son the plant acts as a pump, drawing from below through 
the roots the water which it needs for various purposes, 
and discharging it into the air. It was found that in 
Wisconsin 309.8 tons of water were evaporated by the 
plant for each ton of dry matter in the crop. Four tons of 
dry matter to the acre is not an unusual product wdth 
maize, requiring 1,239.2 tons or 10.4 inches of w^ater for 
its growth, the equivalent of about five-eighteenths of an 
average annual rainfall. This is a fact of great significance 
to the stock-feeder. His success begins with proper hus- 

c 



34 THE FEEDING OF ANIMALS 

banding of the plant-food resources of the farm, of which 
water is an important factor. 

43. Water in feeding-stuffs. — Cattle foods, whether 
in the green or air-dry condition, always contain more 
or less water. The proportion is greatly variable, depend- 
ing upon several factors. With the green foods, the range 
of percentages is similar to that of the living plants pre- 
viously noted. As, however, forage plants are used at 
varying lengths of time after cutting, and as a loss of 
moisture begins immediately after the plant is severed 
from its soiu*ce of water-supply, the amount of dry matter 
in a green forage crop is somewhat uncertain, unless a 
water-determination is made in the material exactly as 
it is fed. In all experimental work this precaution is 
necessary to accuracy. Roots and potatoes contain a 
large proportion of water, which, owing to their struc- 
ture, is slowly evaporated. In a cool, moist cellar, their 
water-content will remain practically unchanged for a 
long time; in a warm, dry room, evaporation occurs and 
they shrivel and lose weight. 

44. Conditions affecting water-content of feeds. — • 
The water-content of air-dry foods varies with the con- 
dition in which they were stored, the length of time after 
storage, and the percentage of moisture in the air. Early 
cut hay often goes to the barn less perfectly cured than 
the late cut, and all hay dries out more than is generally 
realized during the first few months of storage. Con- 
cerning these points, the writer has obtained data through 
experiments at the Maine State and Pennsylvania State 
colleges. Fourteen lots of hay, some early cut and some 
late cut, were weighed when stored and again after 
remaining in the barn for several months. The results 
follow: 



COMPOUNDS OF NUTRITION 



35 



Table VIII 





Early 
cut 

as 
stored 


Early 

cut 

after 

several 

months 


Percent 
loss 


Late 

cut 

as 

stored 


Late cut 

after 
several 
months 


Per cent 
loss 




Pounds 


Pounds 




Pounds 


Pounds 




Timothy ..... 1881 


3634 


2307 


36.5 


4234 


3390 


19.9 


Timothy . 






1882 


3634 


2556 


29.7 


3802 


3168 


16.7 


Timothy . 






1881 


5000 


3922 


21.6 


5270 


4035 


23. 


Timothy . 






1882 


3570 


3037 


14.9 


4017 


3413 


15. 


Clover . . 






1882 


2110 


1215 


42.4 


1520 


1130 


25.6 


Timothy . 






1888 


2815 


2470 


12.2 


2790 


2420 


13.3 


Timothy . 






1889 


5070 


4225 


16.6 


6208 


5086 


18.1 


Average 












24.9 






18.8 



General average loss, 22.2 per cent. 

It is probable that hay seldom loses less than one- 
eighth of its weight during storage, and often much more. 

As illustrating the variations in the proportions of 
water in hay due to changes in air moisture, reference is 
made to observations by Atwater. He found that dry 
hay hung in bags in a barn varied in water-content 
between 7.5 per cent and 13.6 per cent during the 
months of May, June, and July. Hay in large masses 
would change less, but would be affected, doubtless, by 
long periods of very dry weather or very wet. 

45. Relation of water to preservation of cattle foods. — 
The proportion of moisture in coarse foods and grains 
has much to do with their preservation in a sound con- 
dition. New hay and grains when packed in large masses 
are subject to fermentations which injure their quality 
and diminish their food value. This is due to the fact that 
sufficient moisture is present to allow the growth of low 
forms of life with certain attendant chemical changes. 
Feeding-stuffs containing 20 per cent or more of w^ater — 
and this is likely to be the case with clover, rowen, field- 



36 THE FEEDING OF ANIMALS 

cured corn fodder and stover, new oats and new corn — 
when stored in large quantities are almost certain to heat 
and become musty or moldy, always involving a loss of 
nutritive value. (See Par. 306.) 

46. Water in the animal. — ^Water is an important and 
abundant constituent of animal organisms, from the 
lowest to the highest forms. The blood, which is from 
one-thirtieth to one-twentieth the weight of the bodies of 
farm animals, is at least four-fifths water, while the soft 
tissues have been found to contain from 44 to 75 per 
cent, according to the species, age, and condition of the 
animal. The most extensive and complete analyses so 
far made of the entire bodies of animals were performed 
by Lawes and Gilbert at Rothamsted, England. In this 
country, four steers were analyzed at the Maine Experi- 
ment Station, and in the study of human-nutrition 
problems many determinations of water have been made: 

Table IX. Water in Entire Body Per cent 

Ox, well fed, Lawes & Gilbert 66.2 

Ox, half fat, Lawes & Gilbert 59. 

Ox, fat, Lawes & Gilbert 49.5 

Steer, 17 months old, medium fat, Me. E. S 59. 

Steer, 17 months old, medium fat, Me. E. S 56.3 

Steer, 27 months old, fat. Me. E. S 51.9 

Steer, 27 months old, fat. Me. E. S 52.2 

CaK, fat, Lawes & Gilbert 64.6 

Sheep, lean, Lawes & Gilbert 67.5 

Sheep, well fed, Lawes & Gilbert 63.2 

Sheep, half fat, Lawes & Gilbert 58.9 

Sheep, fat, Lawes & Gilbert 50.9 

Sheep, very fat, Lawes & Gilbert 43.3 

Swine, well fed, Lawes & Gilbert 57.9 

Swine, fat, Lawes & Gilbert 43.9 

Chicken, flesh 74.2- 

Fowl, flesh 65.2 

Goose, flesh 42.3 

Turkey, flesh . . : .... .- . . 55.5 



COMPOUNDS OF NUTRITION 37 

It is very evident that, in general, considerably more 
than half of the weight of the bodies of our domestic ani- 
mals consists of water, the limits observed in all species 
and conditions here mentioned being 42.3 and 74.2 
per cent. 

47. Variations of water-content of animal bodies. — 
The percentage of water varies with the species, age, and 
condition. Swine carry a notably small proportion. The 
calf's body, even though fat, is comparatively watery. 
It is very noticeable that with oxen, sheep, and swine the 
lean animals contain a much larger proportion of water 
than the fat. This does not necessarily mean that in the 
process of fattening the fat is substituted for water, and 
so expels it from the organism, but that the increase has 
a much smaller percentage of water than the body in its 
original lean condition. This is well illustrated by the 
data from two independent investigations at Rothamsted 
and at the Maine Experiment Station. The former investi- 
gation showed that w^hen swine, sheep, and oxen were 
fattened the increase contained from 20 to 24 per cent 
of water, this being half the proportion found in the entire 
bodies of the lean animals. The Maine Station results 
established the fact that in the increase of two steers 
from the age of seventeen to twenty-seven months, dur- 
ing which time a fattening ration was fed, there was 42 
per cent of water, the bodies of the younger steers hav- 
ing 58.2 per cent. It is a common remark among unscien- 
tific people that beef from mature animals ''spends" 
better than that from young, the same observation being 
made in comparing lean and fat beef. Modern investiga- 
tion shows clearly that the reason for this lies partly in 
the difference in water-content. Dry matter, and not 
water, is the measure of food value. 



38 THE FEEDING OF ANIMALS 

ASH 

The ash or mineral part of plants and animals has 
occupied a minor place in the discussions which pertain 
to the principles and problems of animal nutrition. In the 
past chief attention has been given to the carbon com- 
pounds of living organisms, while the compounds of the 
mineral world, in their relation to foods and to nutritive 
processes, have generally been passed by with too brief 
discussion. It is desirable to gain a clear understanding 
of the combinations, distribution, and functions of the 
constituents of the ash, for their importance in animal 
nutrition is no less than pertains to the carbon compounds. 

48. Mineral compounds in the ash of plants and 
animals. — As previously stated, the mineral portion of a 
plant or animal is measured by the ash or residue after 
combustion, the principal ingredients of which are the 

following : 

Table X 
Acids Bases 
Hydrochloric acid . . . HCl. Potash K2O 



Sulfuric acid 
Phosphoric acid 
Silicic acid . . 
Carbonic acid 



. H2SO4 Soda NaaO 

. H6P2O8 Lime CaO 

. Si02 Magnesia MgO 

. CO2 Iron oxid Fe203 



Other mineral compounds are found in the various 
forms of vegetable life, but those mentioned are all that 
we need to discuss at length. 

The acids and bases do not exist in the ash as shown, 
but they are united to form salts, and so we have the 
chlorides, sulfates, phosphates, and carbonates of potas- 
sium, sodium, calcium, magnesium, and iron. These 
are nearly all familiar objects in common life, as, for 
instance, sodium chloride (common salt), potassium 



COMPOUNDS OF NUTRITION 39 

chloride (the muriate of potash of the market), potassium 
sulfate (the sulfate of potash of the market), calcium sul- 
fate (of which gypsum or land-plaster is composed), cal- 
cium phosphate (burned bone is chiefly this compound), 
potassium phosphate (a compound of phosphoric acid 
and potash found chiefly at the druggist's), and calcium 
carbonate (limestone). 

49. Rearrangement of ash elements during ignition. — 
It should be remembered that the compounds in the ash 
are not necessarily those of the plant or animal. During 
the ignition of plant or animal substance, organic com- 
pounds are broken up, certain acid and basic elements of 
which enter into other combinations in the salts of the 
ash. Much of the lime in the ash is in union with carbonic 
acid, which in the plant may have been associated with 
vegetable acids, such as oxalic and tartaric, and part of 
the sulfur and phosphorus of the ash comes from cer- 
tain carbon compounds. 

The salts of the ash differ greatly in their properties. 
Some are soluble in water, others are not. To the former 
class belong all the chlorides, and the potassium and 
sodium sulfates and phosphates. The normal phosphates 
of calcium and magnesium are insoluble in water, but 
soluble in various acids. These facts are important in 
showing what salts may be found in the plant and animal 
juices, and what effect leaching with water or other sol- 
vents might have on the inorganic portion of cattle foods. 

50. The ash compounds of plants. — Upon incinera- 
tion, all plants and feeding-stuffs yield an ash residue 
which has been termed the mineral part of the plant. The 
ash elements are important in this connection because 
they are the main source of the same elements of the 
animal body. These may be held in plant tissue in three 



40 



THE FEEDING OF ANIMALS 



ways: in organic combinations and as the inorganic salts 
of plant solutions, crystals and incrustations. Outside 
of phosphorus and sulfur, little is known of the relations 
to plant structure of the important ash elements, such as 
potassium, calcium, and magnesium. Their place as 
bases in organic structures is not fully understood. 

51. Variations of plant ash. — The ash from different 
plants and feeding-stuffs is by no means uniform in com- 
position and quantity, even in the same species or class 
of materials, although with the grains there is some degree 
of uniformity in this respect. Certain factors cause varia- 
tions, such as species, stage of growth, fertility, the part 
of the plant, and changes due to manufacturing processes. 

52. Variations of ash due to species. — Different species 
of plants, and consequently different feeding-stuffs, 
are greatly unlike in their content of mineral matter. 
The figures of Table XI illustrate this fact : 

Table XI 



Mixed grasses . . 
Timothy grass . . 
English ray grass 
Red clover, in bloom 
Seradella, in bloom 
Buckwheat .... 

Potatoes 

Sugar-beets . . . . 

Turnips 

Carrots 

Winter wheat . . . 

Oats 

Maize 

Field beans .... 



Niunber of 
analyses 



106 

9 

11 

113 

3 

17 

59 

149 
32 
11 

110 
57 
15 
19 



Per cent 
ash 



7. 
6.8 
12.1 
6.9 
9.8 
8.2 
3.8 
3.8 
8. 
5.8 
2. 
3.1 
1.4 
3.6 



COMPOUNDS OF NUTRITION 



41 



As a rule forage crops contain a higher percentage or ash 
than do the grains. These variations pertain not alone to 
the quantity of ash but to the proportions of compounds 
which it contains: 

Table XII. The Mineral Compounds op Plants and Feeding- 
Stuffs (Per Cent in the Dry Matter) 



V 


O 




-n 


•c 




o 


o 


o 


-a-i 


9:3 








o 


rfl '^ 


3«i 


h- 1 


PH 


cc 



Mixed grasses . . . 
Timothy hay . . . 
Red clover in bloom 
White clover . . . 

Alfalfa 

Buckwheat . . . . 

Roots 

Potatoes 

Sugar-beets . . . . 
Fodder beets . . . 

Turnips 

Carrots 



Grain 

Winter wheat . 

Oats 

Summer barley 
Maize kernel 

Peas 

Field beans . . 



1.86 
2.37 
2.21 
1.57 

1.74 
2.54 



2.27 
2.03 
3.96 
3.64 
2.02 



.61 
.56 
.56 
.43 
1.18 
1.51 



.23 
.12 
.13 
.53 
.13 
.19 



.11 
.34 

1.23 
.79 

1.16 



.04 
.05 
.06 
.02 
.03 
.04 



1.11 
.55 
2.39 
2.21 
3. 
3.32 



.10 
.23 

.28 
.85 
.62 



.06 
.11 
.07 
.03 
.13 
.18 



.48 
.22 
.75 
.69 
.36 
1.09 



.19 
.30 
.83 
.30 
.24 



.24 
.22 
.23 
.22 
.22 
.26 



.11 


.50 


.36 


.06 


.80 


.19 


.07 


.66 


.22 


.15 


.94 


.54 


.14 


.63 


.42 


.12 


.50 


.30 


.04 


.64 


.25 


.04 


.47 


.16 


.06 


.65 


.23 


.06 


1.02 


.90 


.05 


.70 


.35 


.03 


.93 


.01 


.04 


.80 


.06 


.03 


.92 


.05 


.01 


.66 


.01 


.02 


.98 


.09 


.02 


1.41 


.12 



2. 

2.19 
.18 
.33 
.70 
.09 



.08 
.09 
.15 
.15 
.13 



.04 
1.22 
.68 
.03 
.02 
.02 



.43 
.35 
.26 
.31 
.22 
.06 



.13 
.18 
.75 
.41 

.25 



.03 
.03 
.01 
.04 
.06 



These figures show that potash, hme, magnesia, and 
phosphoric acid are the prominent mineral compounds 
of the plant ash, and it is with them that we find the 
important variations. The true grasses differ from the 
clovers and related plants in containing much less lime 
and greatly more silica, the phosphoric acid and potash 
not being greatly unlike in the two cases. As a source of 
lime, then, the clover hay is superior. Potatoes and roots 
have an ash richer in potash and poorer in lime than are 



42 



THE FEEDING OF ANIMALS 



the coarse fodders. The grains with hulls contain much 
silica, and those like wheat and corn but little. The seeds 
of the legumes are richer in potash and lime than those 
of the grasses. The maize kernel is especially poor in 
lime. 

53. The distribution of mineral compounds in the dif- 
ferent parts of the plant. — Because the farmer separates 
his crops into grain and straw, and the manufacturer goes 
farther and divides the grain into parts, thus modifying 
the character of feeding-stuffs, especially by-products, 
it is necessary to consider just how the mineral compounds 
are distributed in the stalk, leaves, and fruit, especially 
of the cereal-grain plants. A comparison of the straws 
and grains shows striking dissimilarities: 



Table XIII. Per Cent 


IN THE Dry Matter 








o 


i 

O 

P-. 


03 

-a 

O 

m 


a; 

a 


1 
1 


(0 

o 

c 
o 
u 
1— I 


o 


'o 


c8 


'u 
O 


Wheat — 
Straw . . 
Kernel 

Oats- 
Straw . . 
Kernel 

Maize — 
Straw . . 
Kernel 

Peas — 
Straw . . 
Kernel 




5.4 
2. 

7.2 
3.1 

5.3 
1.4 

5.1 

2.7 


.73 
.61 

2.07 
.56 

1.93 
.43 

1.17 
1.18 


.07 
.04 

.24 
.05 

.06 
.02 

.21 
.03 


.31 
.06 

.50 
.11 

.58 
.03 

1.89 
.13 


.13 
.24 

.26 
.22 

.30 

.22 

.41 
.22 


.03 
.03 

.08 
.04 

.12 
.01 

.09 
.02 


.26 
.93 

.33 

.80 

.44 
.66 

.41 

.98 


.13 
.01 

.23 
.06 

.28 
.01 

.32 
.09 


3.62 
.04 

3.34 
1.22 

1.53 
.03 

.35 
.02 


.09 

.31 
.03 

.07 
.01 

.29 
.04 



The straws contain more mineral matter than the 
grains. In the straws there is much more potash, lime, 
and silica than in the grains, while phosphoric acid exists 
in larger proportions in the latter. 



COMPOUNDS OF NUTRITION 



43 



The roots and leaves of beets and turnips present a 
striking difference in mineral-content: 

Table XIV. Per Cent in the Dry Matter 



















-3 








J3 








03 


<o 




o 

03 








O 


o 


o 

m 






o 

c 
o 

1— 1 


o 


1 


c3 




Sugar-beets — 






















Roots .... 


3.8 


2.03 


.34 


.23 


.30 


.04 


.47 


.16 


.09 


.18 


Leaves . . . 


14.8 


3.90 


2.05 


3. 


1.69 


.08 


.71 


.79 


1.51 


1.26 


Fodder beets — 






















Roots .... 


7.6 


3.96 


1.23 


.28 


.83 


.06 


.65 


.23 


.15 


.75 


Leaves . . . 


15.3 


4.71 


2.98 


1.63 


1.46 


.22 


1. 


.86 


.56 


2.45 


Turnips — 






















Roots .... 


8. 


3.64 


.79 


.85 


.30 


.06 


1.02 


.90 


.15 


.41 


Leaves . . . 


11.6 


2.73 


1.10 


3.83 


.46 


.18 


.85 


1.09 


.45 


1.18 



There appears to be a tendency for mineral compounds 
to accumulate in the leaves of plants, and leafy plants 
are, as a rule, those which appropriate these most freely. 

The ash of the outside of the stem and of the husks of 
seeds is in relatively large proportions, due sometimes to 
an excess of silica. Husked rice kernels contain not over .5 
per cent of ash, while the husks contain 39 per cent or over. 

54. Influence of manufacturing processes on the ash 
constituents. — The cattle-food market is abundantly 
supplied with by-products from certain manufacturing 
industries, such as milling, brewing, and starch produc- 
tion. One prominent by-product is wheat bran. As this 
is the outside of the kernel, we would naturally expect, 
in view of the previous statements, that it would be rich 
in mineral compounds, and we find such to be the case. 
The wheat kernel contains about 2 per cent of ash, wheat 
bran about 6 per cent, and wheat flom* about .5 per cent. 
Bran is rich in needed mineral compounds. 



44 



THE FEEDING OF ANIMALS 



In brewing, the kernels of barley are subjected to a 
leaching process which results in taking out the soluble 
mineral salts, chiefly the salts of potassium, calcium, and 
sodium, leaving behind, in part, the compounds of lime 
and magnesium. This fact is made clear by comparing the 
analysis of the ash of barley with that of brewers' grains: 

Table XV. Partial Composition of Ash (Per Cent) 





Potash 


Soda 


Lime 


Mag- 
nesia 


Phos- 
phoric 
acid 


Summer barley 


.56 


.06 


.07 
.64 


.23 
.45 


.92 


Brewers' grains .... 


.15 


1.69 









As a source of phosphoric acid and lime the brewers' 
grains are more efficient, pound for pound, than the 
original barley grains. 

55. The mineral compounds of animal bodies. — ^The 
mineral compounds of animals are nearly similar in kind 
to those of plants, but are very different in relative pro- 
portions. This is made plain by a comparison of the 
figures given below: 



Table XVI. 


Ash 


IN Plants and Animals 








Is 


A 
^ 


eS 


a> 


2 
c 


c 


3 
'S 

03 
O 

1 


e3 


'u 
o 






.*j 


•n 


g 


c3 


2 c3 


^ 








o 


o 


o 




§ 


ji 


;3 


^H 


M 




H 


Pm 


m 


'^ 


Ph 


tc 


\n 


O 




Per 


Per 


Per 


Per 


Per 


Per 


Per 


Per 


Per 


Dry substance 


cent 


cent 


cent 


cent 


cent 


cent 


cent 


cent 


cent 


Timothy hay . . . 


6.8 


2.4 


.12 


.55 


.22 


.80 


.19 


2.2 


.35 


Maize kernel . . . 


1.4 


.43 


.02 


.03 


.22 


.66 


.01 


.03 


.01 


Wheat kernel . . . 


2. 


.61 


.04 


.06 


.24 


.93 


.01 


.04 




Fresh bodies — 




















Fat ox 


3.9 


.14 


.12 


1.74 


.05 


1.56 




.01 




Fat sheep .... 


2.9 


.14 


.13 


1.19 


.04 


1.13 




.02 




Fat swine .... 


1.8 


.10 


.07 


.77 


.03 


.73 









COMPOUNDS OF NUTRITION 45 

Potash is much less pFominent in the composition of 
the animal than is the case with plants, and phosphoric 
acid and lime are much more so. In general, more than 
80 per cent of the ash of the animal body consists of phos- 
phoric acid and lime in combination as calcium phosphate, 
whereas these two compounds constitute less than one- 
fifth of the ash of hay and less than one-half of the ash 
of maize and wheat kernels. 

56. The distribution of inorganic compounds in the 
animal body. — ^The bones contain a very large proportion 
of the ash constituents found in the animal body, the soft 
parts being poor in mineral salts. Between 60 and 70 
per cent of the ash comes from bone, and the bony frame- 
work is from 6 to 9 per cent of the entire bodies of domes- 
tic animals. Williams and Emmett found that the total 
ash in the bodies of pigs forty to forty-three weeks old 
was distributed among the parts as follows: about four- 
fifths in skeleton, one-ninth in the boneless meat and 
about one-sixteenth in the offal, blood, and the jowl and 
intestinal fats. Of the water-soluble ash, only about one- 
twelfth was found in the skeleton, with about three-fifths 
in the boneless meat. This distribution of the ash was not 
the same in pigs forty to forty-three weeks of age as for 
pigs eighteen weeks of age. The offal and carcasses of 
the younger animals contained practically twice as much 
as those of the older pigs, while the skeletons contained 
only about three-fourths as much. More than 80 per 
cent of the ash of bone is calcium phosphate, which is 
associated with calcium carbonate, calcium fluoride, cal- 
cium chloride, and magnesium phosphate. 

The bones of all species of animals show a remarkable 
similarity of composition, the average of which would not 
be far from the following: 



46 THE FEEDING OF ANIMALS 

Table XVII. In 100 Parts of the Ash of Bone (Average) 

Calcium phosphate • 83.9 

Calcium carbonate ...... 13. 

Calcium in other combinations .35 

Fluorine 23 

Chlorine 18 



97.66 



57. Ash elements in the soft tissues. — The muscular 
tissue and other soft parts of the animal body contain 
less than 1 per cent of incombustible materials. The ash 
of flesh is mostly phosphoric acid and potash, accompanied 
by comparatively small amounts of soda, lime, and mag- 
nesia and minute quantities of chlorine and iron. Unques- 
tionably, potassium phosphate is the predominating salt 
in flesh, as calcium phosphate is in bone. 

58. Ash elements in the blood. — ^The blood contains 
a variety of mineral substances, the chief of which is 
sodium chloride, or common salt, although a minute 
amount of iron is present, having a most important func- 
tion. In the bile, soda is abundant, combined mostly 
with the peculiar organic acids of this secretion. Chlorine 
is a constant constituent of the gastric juice, its presence 
as chlorhydric acid being essential to digestion. The 
preceding are some of the prominent facts concerning 
the inorganic compounds of the animal body, but they 
are only a brief suggestion of the knowledge which per- 
tains to this part of animal chemistry. 



CHAPTER V 

THE COMPOUNDS OF ANIMAL NUTRITION, 
CONTINUED— THE NITROGEN COMPOUNDS 

The nitrogen compounds of the vegetable and animal 
kingdoms have received much attention from scientific 
investigators and writers during the past fifty years. It 
has been generally taught that certain members of this 
class of substances are the ones most important in the 
domain of animal nutrition, and many writers have given 
to these a prominent place in discussing the relative 
value of feeding-stuffs and have almost ignored the other 
nutrients. It is now conceded that relatively the func- 
tion and value of protein have been unduly magnified. 
The present tendency is toward a fuller discussion of the 
office and value of the non-nitrogenous bodies. 

59. The importance of protein. — ^There can scarcely 
be any disagreement, however, concerning the general 
proposition that the proteins play a leading part in the 
processes and economy of animal nutrition. This is true 
for several reasons: 

(1) The nitrogen compounds are those fundamental 
to the energies of the living cells which make up the tis- 
sues of plants and animals. The basic substance of the 
active cell is protoplasm, a complex nitrogenous body, 
which Huxley called "the physical basis of life." Around 
this primal substance seem to center all vital activities, 
especially the transformation of the raw materials of the 
inorganic world into the organized structures of life. 

(47) 



48 THE FEEDING OF ANIMALS 

(2) These compounds are structurally essential to the 
growth of animal tissues and to the formation of milk. 
The significance of this fact is intensified by their paucity 
in many of the feeding-stuffs that are ordinarily pro- 
duced on the farm. 

PROTEIN 

For the sake of brevity and convenience, the nitro- 
gen compounds of cattle foods, both vegetable and 
animal, have been designated as a class by the single 
term protein. When, therefore, it is stated that a feeding- 
stuff contains a certain percentage of protein, reference 
is made to the total mass of nitrogen compounds present, 
which may be many in number and of greatly differing 
properties. 

60. How protein is determined. — ^The proportion of 
protein (total nitrogen compounds) in a feeding-stuff as 
given in tables of feeding-stuff analyses is ascertained by 
determining the percentage of total nitrogen and then 
multiplying this by the factor 6.25. This method is based 
on the assumption that the average percentage of nitro- 
gen in protein compounds is 16, which is not true to so 
close a degree of approximation as was formerly believed 
to be the case. It may happen in some instances that a 
determination made in this way is sufficiently accurate, 
while in other cases the margin of error is large. Recent 
investigations with perfected methods show percentages 
of nitrogen in the numerous single protein substances 
found in the grains ranging from 15.25 to 18.78. These 
are largest in certain oil seeds and lupines and smallest 
in some of the winter grains. Ritthausen, a prominent 
German authority, conceded that the factor 6.25 should 
be discarded, and suggests the use of 5.7 for the larger 



THE NITROGEN COMPOUNDS 49 

number of cereal grains and leguminous seeds, 5.5 for 
the oil and lupine seeds, and 6 for barley, maize, buck- 
wheat, soja-bean, and white bean (Phaseolus), rape and 
other brassicas. Nothing short of inability to secure 
greater accuracy justifies the longer continuance of a 
method of calculation which is apparently so greatly 
erroneous. 

61. So-called proteins greatly iinlike. — ^As previously 
stated, protein is the accepted name for a class of com- 
pounds. Just how there came about such a grouping 
of a large number of substances under a single head it is 
not necessary to consider in this connection, but it should 
be naade clear that the individual compounds which are 
included under this term are greatly unlike in their 
chemical and physical properties; and it is known that 
they differ materially in their nutritive functions. 

62. Classification of proteins. — It is very evident that 
it is not only convenient, but necessary, to classify such 
a heterogeneous group of bodies into subdivisions more 
nearly alike in their characteristics. 

The most recent classification is one recommended by 
committees representing certain scientific bodies.* Doubt- 
less this classification is only temporary and will be 
modified as our knowledge of the compounds of nutrition 
is enlarged. The grouping now agreed upon is based on 
chemical constitution; at the same time the lines of cleav- 
age appear to have reference to nutritive function. As will 
be noticed later, other bodies are related to metabolism 
and growth which it is not now possible to classify as 
they have not yet been isolated and their chemical con- 
stitution is undetermined. The terms used in this classi- 
fication are explained in the text which follows: 

*Ain. Jour. Phys., Vol. XXI. 
D 



50 



THE FEEDING OF ANIMALS 



'Simple . . ■ 



Proteins 



Albumins 

Globulins 

Glutelins 

Alcohol solubles 

Albuminoids 

Histones 

Protamines 



Conjugated 



Nucleo-proteins 
Glyco-proteins 
Phospho-proteins 
Haemoglobins 
. Lecitho-proteins 



Primary 
derivatives 



.Derived . • 



Secondary 
derivatives 
r Extractives 
Non-proteins< Amides 

(.Amino acids 



I'Proteans 

< Meta proteins 
(^Coagulated proteins 

^Proteoses 

< Peptones 
(Peptides 



Certain changes in terms and classifications should be 
noted. The term proteid is abandoned, and the term 
albuminoid is made to refer to the bodies formerly classed 
as collagens or gelatinoids. The newer classification 
groups the proteins on the basis of constitution and char- 
acteristic properties. 

Other nitrogen compounds are included with the pro- 
teins by the present methods of chemical analysis, such as 
alkaloids and nitrates, but these are so uncommon in 
foods, or are present in such small quantities, that they 
may be safely ignored. 

63. The true proteins. — ^The proteins are the main and 
important nitrogen compounds either in the plant or in 
the animal. The nitrogenous bodies of seeds are little else 
than such proteins, while young plants, and especially 



THE NITROGEN COMPOUNDS 



51 



roots, such as beets and turnips, contain more nitrogen 
in the non-protein form. Proteins are the chief constit- 
uents of muscular tissue. Their chemical constitution is 
not definitely known, but it is generally considered 
to be very complex, even to the extent of several 
thousand atoms. These bodies are constructed from 
the simpler ones of the inorganic world through the 
vital energies of plants, and in order to serve the 
purposes of nutrition they must come to the animal fully 
organized. 

64. Ultimate composition of proteins. — ^The ultimate 
composition of proteins, that is, the proportions of the 
elements which they contain, has been carefully studied, 
and while there are material differences among them in 
this respect, the limits of variation are not especially 
wide, as can be seen from the follow^ing figures according 
to Osborne:* 



Table XVIII 


. Composition of Some Typical Proteins 




Carbon 


Hydro- 
gen 


Nitro- 
gen 


Oxygen 


Sulfur 


Iron 


Phos- 
phorus 




Per cent 


Per cent 


Per cent 


Per cent 


Per cent 


Per cent 


Per cent 


Egg-albumin . . 


52.75 


7.10 


15.51 


23.02 


1.616 






Lact-albumin . . 


52.19 


7.18 


15.77 


23.13 


1.73 






Leucosin .... 


53.02 


6.84 


16.80 


22.06 


1.28 






Serum-globulin 


52.71 


7.01 


15.85 


23.32 


1.11 






Myosin 


52.82 


7.11 


16.67 


22.03 


1.27 






Edestin ... 


51.50 


7.02 


18.69 


21.91 


.88 






Legumin . . . 


51.72 


6.95 


18.04 


22.90 


.385 






Casein 


53.13 


7.06 


15.78 


22.37 


.80 




.86 


Ovovitellin . . . 


51.56 


7.12 


16.23 


23.24 


1.028 




.82 


Gliadin 


52.72 


6.86 


17.66 


21.73 


1.027 






ZeiQ . ' 


55.23 


7.26 


16.13 


20.78 


.60 






Oxyhemoglobin 


54.64 


7.09 


17.38 


20.16 .39 .335 





'Chemistry of Food and Nutrition," Sherman, page 35. 



52 THE FEEDING OF ANIMALS 

We see that the number of elements ordinarily found 
in the proteins is five, nitrogen and sulfur being those that 
chiefly distinguish these bodies from all others which 
make up the mass of combustible matter. Two other 
elements are found in certain of these bodies, as, for 
instance, phosphorus in casein and ovovitellin and iron 
in a constituent of blood. 

65. Familiar examples of proteins. — Proteins are 
familiar objects, and their properties are matters of 
common observation. The tenacious cud of gum from 
wheat gluten, the strings of coagulated albumin which 
separate from the cold-water extract of fresh lean beef 
that is brought to the boiling-point, the hardening of the 
white of an egg into a tough mass as it is dropped into 
boiling water, the stiffening of the muscular tissue of the 
slaughtered animal or the rapid formation of strings of 
fibrin in the cooling blood — in all these instances there 
are manifested certain chemical or physical properties 
which pertain to these most important and widely uti- 
lized compounds. 

SIMPLE PROTEINS 

66. The albumins. — ^The albumins have several sources. 
They are found in the juice of plants, in certain liquids 
of the animal body such as the serous fluids, in the cell 
substance of muscular tissue, in blood and milk, 
and abundantly in eggs. Unlike other proteins, 
these compounds are freely soluble in pure cold water, 
and when such a solution is heated to the boiling- 
point, they separate from solution by coagulation and 
become insoluble unless acted upon by some strong 
reagent. 



THE NITROGEN COMPOUNDS , 53 

When macerated beef is treated with cold water the 
albumin in it goes into solution, and if this extract is 
boiled the albumin separates in clotted masses. 

The clear serous fluid that is left after removing the 
clot from blood contains albumin. After the casein is 
removed from milk by acid or rennet, the albumin of the 
milk remains in the whey. It is this which in part causes 
milk to clot if brought to the boiling-point. As stated, one 
example of this class of proteins is the white of an ^gg, 
which, when cooking in boiling water, becomes a hard, 
coagulated mass. Albumin in the serous fluids and in 
blood is called serum-albumin; in milk, lact-albumin, and 
in eggs, ova-albumin. 

A small proportion of the proteins of plants is found to 
be albumin; for instance, Osborne found .3 to .4 per cent 
in wheat, .43 per cent in rye, .3 per cent in barley, .5 per 
cent in soja-beans, and some in most seeds. This possesses 
essentially the same characters as the animal albumin 
described previously. Whenever a vegetable substance 
is leached with water, it is probably this protein which 
would be the first to suffer removal or destructive 
fermentation. 

67. The globulins. — ^These proteins are usually asso- 
ciated with albumins. When animal tissues are treated 
wdth water, but a small part of the proteins dissolve. If, 
however, we add to the water a mineral salt, especially 
common salt (sodium chloride), sufficient to secure a 
10 per cent solution, an additional and considerable 
amount of protein may be extracted. Certain compounds 
so extracted are called globulins, and differ from the 
albumins in being practically insoluble in pure water and 
in a saturated solution of certain mineral salts, such as 
sodium chloride. The so-called globulins form an impor- 



54 THE FEEDING OF ANIMALS 

tant part of the protein-content of plants and of animal 
tissues, both in quantity and in having a maximum 
nutritive usefulness. 

68. Plant globulins. — In plants these proteins seem 
to be especially abundant and widespread. Our most 
recent and most reliable knowledge of plant proteins 
comes from investigations by Osborne. In these researches 
the seeds of many species of agricultural plants were 
studied, all of which were found to contain globulins. 
In some the proteins consisted largely of these com- 
pounds. The percentage content in certain seeds was 
determined approximately: 

Table XIX. Globulins in Certain Seeds 



Kidney bean . . . 
Cottonseed meal 
Peas 


Per cent 

. 20. 
. 15.8 

10. 
. 26.2 
.6 


Lentil . . . 
Horse bean . 
Maize . . . 


Per cent 
.... 13. 
.... 17. 
4 


Lupin 

Wheat 


Soybean . . 


. chiefly globulin 



The seeds of the legumes, as a rule, contain the larg- 
est proportion of these proteins, the cereal grains 
having only a very small part of their protein in this 
form. 

From present knowledge, many seeds appear to have 
characteristic globulins which differ among themselves 
in their chemical properties. These have been given 
names derived from the general names of the species in 
which they are found. Thus we have amandin in almonds, 
avenalin in oats, corylin in walnuts, excelsin from the 
Brazil-nut, phaseolin in several species of beans, glycin 
in the soybean, maysin in maize, vicilin in horse beans, 
lentils, and peas, vignin in the cowpea, and tuberin in 
the potato. One globulin called edestin appears to be 



THE NITROGEN COMPOUNDS ' 55 

quite generally distributed in the seeds of agricultural 
plants, having been found in a larger number than 
any other protein yet discovered, including all the 
cereals, castor bean, cottonseed, flaxseed, hemp, squash, 
and sunflower, although it is not abundant in any of 
these. 

69. Animal globulins. — ^The animal globulins exist 
abundantly in muscle and blood. If finely divided, well- 
wa^ed muscle (lean meat) is treated with a 10 per 
cent salt solution, first by rubbing it in a mortar with 
fine salt, and then adding enough water to secure the 
proper strength of solution, a globulin is dissolved which is 
derived from a muscle protein designated by some authors 
as myosin. It is believed that myosin coagulates in the 
muscle upon the death of an animal forming a clot some- 
times called myosin-fibrin. The theory has been proposed 
that myosin acts as a "mother" substance in the muscle 
from which myosin-fibrin is formed in much the same 
way as fibrin is developed in clotting blood from a pre- 
existing body, but no single view as to exactly what 
occurs is fully accepted. Other terminology has been 
proposed, viz., that the mother substance shall be named 
myosinogen to correspond to fibrinogen, myosin being the 
coagulation product. Much confusion and indefiniteness 
exist with reference to the chemistry of muscle proteins. 
There is, nevertheless, a general agreement that rigor 
mortis is due to a clotting of the muscle, accompanied by 
marked chemical transformations. It is held that fer- 
ments are present in the muscle, to the influence of which 
these changes are due, and without which they do not 
occur. 

Another prominent globulin is the fibrinogen found in 
the blood. When blood is drawn from the veins and cools, 



56 THE FEEDING OF ANIMALS 

it clots, which is nothing more than the formation of 
strings of fibrin, perhaps through the influence of a fer- 
ment, which has been named thrombin. Fibrin as such is 
not found in living blood. A remarkable fact is that so 
long as the blood is retained in the arteries and veins, 
even if the animal dies and grows cold, this clotting does 
not appear. 

Serum-globulin is a collective name for several globu- 
lins, which exist in blood-serum and in the other fluids of 
the animal body, such as lymph and its allies, including 
those exudations which pertain to diseased conditions, 
especially dropsical. 

One more protein has been generally classified as a 
globulin, although differing in some respects from the 
other members of this class, and more recently is classed 
as a phospho-protein. Reference is made to vitellin, 
which is the principal protein in the yolk of eggs. It is 
there intimately mixed with certain peculiar phosphorized 
bodies, which we shall notice later. 

70. Glutenins. — ^These form a large part of nitrogen 
compounds of the cereal grains and possibly of other 
seeds. They are insoluble in water, alcohol, and neutral 
salt solutions, but readily dissolve in very dilute acids 
and alkalies. ' The glutenin of wheat, found in the 
tenacious substance that is left after washing the starch 
out of wheat flour, is the best-known protein of this 
class and is an important constituent of wheat flour, 
existing there on the average to over 40 per cent of the 
total protein. 

71. Alcohol-soluble proteins.* — ^Alcohol-soluble pro- 
teins have been found in all the cereal grains so far exam- 

* Osborne and others propose the name prolamins. Science, Vol. 
XXVI, pages 417-427. 



THE NITROGEN COMPOUNDS , 57 

ined. The principal ones to be mentioned are gliadin 
from wheat, zein from corn, and hordein from barley. 
Gliadin is more abundant in the wheat kernel than is the 
glutenin w^ith which it is associated, the two together 
constituting over 80 per cent of the total proteins of that 
cereal. The proportion of gliadin in wheat flour has much 
to do with its quality for bread-making purposes. It ap- 
pears that the best bread flour contains about twice as 
much gliadin as glutenin. 

72. Albuminoids. — ^This term, according to the classi- 
fication still in more or less use in the United States, has 
been understood as including various proteins such as 
the albumins, and globulins. The classification now 
recommended confines the term to proteins found chiefly 
in the animal body in such parts as the cartilages, bones, 
feathers, hair, hoofs, horns, and nails. These proteins 
are also obtained from the threads of silkworms and from 
sponges. The albuminoids have group names, such as 
collagen in cartilage and bone, keratins in feathers, hair, 
hoofs, horns, nails, and similar exterior tissues, fibroin 
in the threads of silkworms, and spongin in the frame- 
work of sponges. 

Gelatine, so well known to the housewife, is derived 
from collagen. When meat containing tendons (cartilage) 
is submitted to the action of boiling water, there is 
obtained in the extract a gelatinous substance which 
becomes evident when the extract is cooled. This gela- 
tine is insoluble in cold water, but dissolves in hot. As a 
dry commercial article, it is a tenacious substance which, 
when prepared in thin layers, is transparent. When col- 
lagen and gelatine are acted upon by tannic acid, as, for 
instance, when the skin of an animal is treated with an 
extract from hemlock or oak bark, the result is a sub- 



58 THE FEEDING OF ANIMALS 

stance which does not putrefy and which gives to the 
tanned hide the properties of leather. Gelatine is much 
used in various food preparations. 

It is characteristic of the keratins such as hair and horn 
that they contain a relatively large proportion of sulfur, 
the analysis of horn and hair showing as high as 5 per 
cent, the average amount in horn being 3.3 per cent. The 
keratin bodies serve to give rigidity and wearing quali- 
ties to certain exterior animal tissues. 

73. Histones, protamines. — ^The proteins in these 
two groups do not occur as such in nature, and are ob- 
tained only by separating them from some combination. 
The two groups are alike in being basic in character 
and in being found in the spermatozoa of fishes. 
Histones have also been obtained from the blood cor- 
puscles of a goose and from the white blood corpuscles 
of thymus glands. 

CONJUGATED PROTEINS 

74. Nucleo-proteins. — ^These are complex, phosphorus- 
bearing proteins that sustain an important nutri- 
tive function. They are regarded as a combination of 
nuclein with an albumin, the nucleins being compounds 
of nucleic acid and albumin, and nucleic acid yielding on 
cleavage phosphoric acid, certain nitrogenous bases known 
as purins, and a carbohydrate. 

The nucleo-proteins are associated with the nuclei of 
the cells that make up both plant and animal tissues. 
They are relatively abundant in glandular tissues such as 
the spleen, pancreas, thymus gland, and liver. The 
spermatozoa masses of fishes are especially rich in these 
compounds. Because certain bases known as purins 



THE NITROGEN COMPOUNDS , 59 

which arise from the cleavage of nucleo-proteins are 
regarded as the progenitors of uric acid, persons with 
uric-acid tendency have been advised to avoid eating 
certain animal foods such as beef and liver, or any others 
known to contain these compounds abundantly. Experi- 
ments show that the feeding of certain tissues rich in 
nucleo-proteins increases the output of uric acid, while 
adding to the diet a large amount of purin-free proteins 
such as albumin does not have this effect. 

75. Glyco-proteins. — These are bodies that upon cleav- 
age are decomposed into a protein and a carbohydrate. 
The best-known glyco-proteins are the mucins that are 
secreted by the mucous membranes of the air passages 
and of the alimentary canal and by certain glands such as 
the salivary. Certain of these compounds contain phos- 
phorus and others do not. 

76. Phospho-proteins. — Like the nucleo-proteins, 
these compounds contain phosphorus, but on cleavage 
do not yield the purin bases. The best-known phospho- 
protein is the casein of milk, a compound exceedingly 
important in human nutrition, especially with the 
young. 

This compound is a secretion of the mammary gland 
of many species of animals, and doubtless originates in 
the gland cells. The casein from different species of 
mammals differs somewhat in chemical and physical 
properties. Casein is insoluble in water, but exists in 
milk in suspension. It is not coagulated by heat but 
curdles when a weak acid is added to milk, as, for instance, 
vinegar. The same result is produced by a generous quan- 
tity of common salt. When milk is received into the 
human stomach, the casein coagulates (the milk curdles) 
through the action of a ferment in the gastric juice and 



60 THE FEEDING OF ANIMALS 

this coagulation is mechanically unlike, at least, with 
milk from different species. The action of this ferment 
on casein is utilized in cheese-making in the development 
of a curd which, with its inclosed fat, is separated 
from the whey and pressed into compact masses and 
later allowed to imdergo certain changes due to other 
ferments. 

Other phospho-proteins exist, one being the vitellin 
in the yolk of eggs which, as prepared, contains 
lecithin. 

77. Haemoglobin. — Blood contains a peculiar com- 
pound known as haemoglobin. When decomposed, it 
separates into a protein, globin, and a coloring matter 
hsemochromogen, which, when charged with oxygen, is 
called haematin. This oxidation changes the haemoglobin 
to oxy-haemoglobin. This haemoglobin in the blood of 
mammals contains, besides carbon, nitrogen, oxygen, and 
hydrogen, sulfur and iron. The latter varies in per cent 
from .34 to .48, and sustains an essential relation to the 
functions of the blood. The blood pigment has the 
property of taking up and releasing oxygen with great 
readiness, carrying its load of oxygen out of the lungs, 
giving it up to oxidation processes in various parts of the 
body, and bringing to the lungs in its place the result- 
ing carbon dioxid to be discharged into the air. The 
blood changes color with the acquisition and loss of the 
oxygen. 

78. Lecitho-proteins. — From the yolk of eggs, the 
mucous membranes, and the kidneys, and doubtless from 
other sources, are obtained a conjugated protein con- 
taining lecithin. The constitution and special function 
of this body are not well understood. 



THE NITROGEN COMPOUNDS - 61 

DERIVED PROTEINS 

These are divided into primary and secondary protein 
derivatives. Primary protein derivatives are those that 
have been slightly modified by the action of water, very 
dilute acids, or enzyms, or are the result of the action of 
acids and alkalies whereby products soluble in weak 
acids and alkalies are formed. Coagulated proteins 
resulting from the action of heat and alcohol are classed 
in this division. 

Secondary protein derivatives are those in which the 
modifying changes (hydrolytic, or the taking up of water) 
through the action of acids or enzyms, have proceeded 
beyond the incipient stage with the formation of bodies 
that are soluble in water. In this division, the most 
important compounds are the proteoses and the peptones, 
the latter having suffered a greater change by hydrolysis 
than the former. 



1. PRIMARY PROTEIN DERIVATIVES 

79. Proteans and metaproteins. — ^When proteins are 
acted on by acids or alkalies, they are modified in 
proportion to the strength of the reacting acid or alkali 
and the length of time that the action continues. With 
acid or alkalies of sufficient strength, there are formed 
products soluble in weak acids and alkalies (meta-pro- 
teins). 

80. Coagulated proteins. — ^There are several agents 
which convert albumins and other proteins into a coagu- 
lated mass, such as a boiling heat, alcohol, and certain 
neutral salts and the action of an enzym. For instance, 



62 THE FEEDING OF ANIMALS 

with albumin from flesh or the white of an egg, boiHng 
water converts it into a coagulum that is insoluble in 
water and is rendered soluble only by such agents as 
acids and alkalies upon heating. 

Dropping a soluble protein into alcohol has the same 
effect. Globulins are, as a rule, affected in the same way. 
The nature of this modification is not known. 

2. SECONDARY PROTEIN DERIVATIVES 

81. Proteoses, peptones. — ^When various proteins such 
as albumin or globulin are subjected to the action of a 
weak acid or of certain enzyms, they undergo what is 
known as hydrolysis. This change involves a cleavage 
(splitting) of the protein body accompanied by the taking 
up of the elements of water. In this way are formed pro- 
teoses and peptones, the latter being proteins that are 
soluble in water. A proteose is an intermediate stage 
between the original protein and a peptone, and it receives 
a name according to its source, as albumose, globulose, 
and caseose, according as an albumin, a globulin, or casein 
is its source. 

Peptone was formerly regarded as the final product of 
enzym action in digestion, but we now know that the 
digestion of the proteins proceeds much farther. These 
hydrolyzed bodies are found abimdantly in the digestive 
tract during digestion, the proteoses as stated being an 
intermediate stage of digestion between the original pro- 
teins and the peptones. This means that the formation 
of the final products of protein digestion is a progressive 
step. Proteoses and peptones may also be obtained by 
laboratory methods. It should be noted that commercial 
peptones are largely proteoses. 



THE NITROGEN COMPOUNDS ' 63 

82. Important properties of the proteins. — ^The pre- 
vious description of the various groups of proteins cannot 
be understood to its fullest extent except by those who 
have a good knowledge of the fundamentals of organic 
chemistry. Nevertheless, the facts given serve to impress 
the important chemical and physical properties which 
these bodies possess, and point to the necessity of study- 
ing them individually in their relation to foods and nutri- 
tion. It is not rational to speak of protein as if the 
term represents an individual entity, but the members 
of this general class of compounds must be considered 
by sub-classes at least, in discussing their place in 
nutrition. 

A fact of importance is the varying constitution of 
the protein molecule, and consequently the possible 
variation in the nutritive function of the individual 
proteins. 

83. The unlike constitution of the various proteins. — 
We have already seen that certain proteins are particu- 
larized in part by containing phosphorus, others sulfur, 
and others iron. A phosphorus-bearing protein may have, 
and undoubtedly does have, a nutritive function that 
cannot be exercised by an albumin not carrying 
phosphorus. 

84. Cleavage products of the proteins. — It is well 
known that when proteins are submitted to the action 
of acids, alkalies, and certain ferments (enzyms) they 
break up into simpler compounds which w^e speak of as 
cleavage products, chiefly amino-acids which are some- 
times designated as the building-stones of the proteins. 
It is very significant that the kinds, and especially the 
proportions, of these products differ greatly with different 
proteins. For instance, the purin bases, which certainly 



64 



THE FEEDING OF ANIMALS 



sustain important physiological relations, are present 
in beef and certain glands used as food, but absent in 
milk and eggs. The variations in the decomposition prod- 
ucts of certain vegetable proteins are striking, as also 
are the differences in this respect between vegetable and 
animal proteins, and these differences have an important 
bearing on the value of the inividual proteins for the 
purposes of growth. The following table taken from 
Hammarsten's "Text-book of Physiological Chemistry," 
seventh edition, is worthy of attention: 



Table XX. Cleavage Products of the Proteins 
Plant Proteins 





Edestin 


Legumin 


Hordein 


Gliadin 


Zein 


GlycocoU 


3.8 


.38 




.68 




Alanine 


3.6 


2.08 


.43 


2. 


9.79 


Valine 


5.6 


1. 


.13 


3.34 


1.88 


Leucine 


20.9 


8. 


5.67 


6.62 


19.55 


Serine 


.33 


.53 


. . 


.13 


1.02 


Aspartic acid . . . 


4.5 


5.3 


, 


.58 


1.71 


Glutamic acid . . . 


18.74 


13.8 


43.19 


43.66 


26.17 


Cystine 


.25 


, , 


, 


.45 


. 


Phenylalanine . . . 


2.4 


3.75 


5.03 


2.35 


6.55 


Tyrosine 


2.1 


1.55 


1.67 


1.2 


3.55-10.1 


Proline 


1.7 


3.22 


13.73 


13.22 


9.04 


Oxyproline .... 


2. 


. 


. 




, , 


Tryptophane . . . 


.38 


. 


, 


1. 


. . 


Histidine 


1.1 


2.42 


1.28 


.61 


.82 


Arginine 


11.7 


10.12 


2.16 


3.16 


1.55 


Lysine , 


1. 


4.29 








Ammonia 


• • 


1.49 


4.87 


5.22 


3.61 



THE NITROGEN COMPOUNDS 



65 





Animal Proteins 










Lact-al- 
bumin 


Ser-al- 
bumin 


Ova-al- 
buinin 


Ser-glo 
bvilins 


Fibrin 


Casein 


VitelUn 


Glycocoll .... 








3.5 


3. 




1.1 


Alanine .... 


2.5 


2.7 


2.2 


2.2 


3.6 


1.5 


.75 


Valine 


.9 




2.5 




1. 


7.2 


2.4 


Leucine .... 


19.4 


20. 


10.7 


18.7 


15. 


9.35 


11. 


Isoleucine . . . 


, 




, 


, 


, , 


1.43 


^ ^ 


Serine 


, , 


.6 


, 




.8 


.5 


^ ^ 


Aspartic acid . . 


1. 


3.1 


2.2 


2.5 


2. 


1.39 


2.13 


Glutamic acid . . 


10.1 


7.7 


9.1 


8.5 


10.4 


15.55 


12.95 


Cystine .... 




2.5 


.3 


1.51 


1.17 


.07 




Phenylalanine . . 


2.4 


3.1 


5.17 


3.8 


2.5 


3.2 


2.8 


Tyrosine .... 


.85 


2.1 


1.77 


2.5 


3.5 


4.5 


3.37 


Proline .... 


4. 


1.04 


3.56 


2.8 


3.6 


6.7 


4.18 


Oxyproline . . . 


. 




, 


, 


, . 


.23 


, , 


Tryptophane . . 


3.07 






. 


, , 


1.5 


, , 


Histidine .... 






1.71 






2.5 


1.9 


Arginine .... 






4.91 




3. 


3.81 


7.46 


Lysine 






3.76 


, , 


4. 


5.95 


4.81 


Ammonia .... 






1.34 


• • 




1.6 


1.25 



In view of later discussions it is well to note in this 
connection certain marked differences in the kind and pro- 
portions of the cleavage products (building-stones) of the 
individual proteins. 

For example, glutamic acid is found in the plant 
proteins in much larger proportion than in animal pro- 
teins; lysine is absent from the alcohol-soluble proteins 
hordein, gliadin, and zein, and proline is found in much 
larger proportion in these than in any others. It is safe to 
conclude that certain plant proteins cannot be rebuilt 
into an equal quantity of animal proteins. 

It should be noted, however, that a comparison of 
vegetable and animal proteins shows in general a close 
resemblance in the kind of building-stones out of which 

£ 



66 THE FEEDING OF ANIMALS 

they are constructed, although the proportions are 
unlike. 

NITROGEN COMPOUNDS THAT ARE NON-PROTEINS 

In the usual method for determining the proteins of a 
food by multiplying the total nitrogen present by a fac- 
tor, there is included in the calculation nitrogen that does 
not come from true proteins, but from compounds that 
possess physical and chemical properties greatly removed 
from those which characterize albumin and other true 
proteins. Their office as nutrients is probably less com- 
prehensive than that of the proteins. 

85. Amino-acids and amides. — ^These compounds re- 
sult from the union of organic acids and the group NH2. 
Whether the resulting compound is an amino-acid or an 
amide depends upon the manner of combination. Cer- 
tain of the amino-acids may be produced in the labora- 
tory by synthesis, but in the main they are obtained 
from the cleavage of protein through the action of acids 
or alkalies or ferments (enzyms). They are found abun- 
dantly in the alimentary canal during the digestion of food 
as a result of the action of the digestive enzyms on pro- 
teins. Amides occur in plants. Asparagine is an amide of 
amino-succinic acid, first found in young asparagus shoots, 
and glutamine is an amide of amino-glutaric acid, found in 
germinating pumpkin seeds. They are soluble in water, and 
consequently are diffusible throughout the plant tissues. 
It is believed that such amides are forms in which the 
nitrogen compounds of the plant are transferred from one 
part to another, as, for instance, from the stem to the seed. 
It has generally been held that these bodies are more abun- 
dant in young plants than in mature. A larger part of the 
nitrogen of roots and tubers is found in these compounds 



THE NITROGEN COMPOUNDS - 67 

than in other foods, the proportion in grains being the 
least, and is very small indeed. Such investigations as 
have been conducted point to the conclusion that amides 
do not function wholly as do the proteins. This is one 
reason for regarding the protein of certain vegetable foods 
as of less value than that of the grains and grain products. 
86. Extractives. — ^These are bodies found in the extract 
obtained from beef with cold water. After the albumin 
has been removed from such an extract by boiling, these 
compounds known as creatin and creatinin chiefly con- 
stitute the nitrogenous solids that remain. Their food 
value is small, for they appear to be largely eliminated 
from the body in the urine without change. 



CHAPTER VI 

THE COMPOUNDS OF ANIMAL NUTRITION, 

CONCLUDED— CARBOHYDRATES, ACIDS, 

FATS, AND OILS 

Much the larger proportion of the dry matter of cattle 
foods consists of non-nitrogenous material. WTiile these 
nitrogen-free compounds have not been regarded as 
fundamentally so important as are the proteins, in quan- 
tity they unquestionably occupy the first rank. The 
activities of plant life are largely devoted to their pro- 
duction, and their use by animal life is correspondingly 
extensive. They may properly be called the main fuel- 
supply of the animal world. Other nutrients aid in main- 
taining muscular activity, to be sure, but these compounds 
are the principal storehouse of that sun-derived energy 
which furnishes the motive power exhibited in all animal 
life. They also fill a necessary office in the formation of 
milk and in the fattening of animals. This class of com- 
pounds greatly predominates in the usual farm crops, 
even in those of the legume family. 

87. Elementary composition of the non-nitrogenous 
compounds. — ^The non-nitrogenous compounds contain 
only three elements — carbon, hydrogen, and oxygen. 
They may be derived, therefore, wholly from air and 
water, and they constitute that portion of foods which is 
drawn from never-failing and costless sources of supply. 
The elementary composition of typical nitrogen-free 
bodies is given in this connection: 

(68) 



CARBOHYDRATES, ACIDS, FATS, OILS 



69 



Table XXI 



Carbon 

Hydrogen 

Oxygen 



CeUu- 
lose 



Percent 

44.4 

6.2 

49.4 



Starch 



Percent 

44.4 

6.2 

49.4 



Glucose 



Percent 

40. 

6.7 
53.3 



Saccha- 
rose 



Percent 

42.1 

6.4 

51.5 



Stearin 



Percent 

76.7 
12.4 
11. 



Olein 



Per cent 

77.4 
11.8 
10.8 



88. Classification of non-nitrogenous compounds. — 

The non-nitrogenous compounds of foods are usually 
divided into two main classes, viz., carbohydrates and 
similar bodies and fats and oils. The first class often 
bears the name nitrogen-free extract, but the carbohy- 
drates are its principal members. Crude fiber belongs in 
this class. The second is known by the chemist as ether- 
extract, because ether is used to extract the fats or oils 
from the vegetable substances in which they are con- 
tained. The actual fat obtained from vegetable foods is 
always less, however, than the ether-extract, because the 
ether takes into solution other compounds than the fats. 
It should be noted that the last two compounds of the 
above table, which are fats, are relatively richer in car- 
bon and hydrogen and poorer in oxygen than the other 
compounds mentioned, which are carbohydrates. This 
fact has an important relation to nutritive value. 

89. The carbohydrates. — In order to understand the 
carbohydrates as individual compounds and in their 
relations to each other and to the processes of nutrition, 
it is necessary to consider them, in general outlines at 
least, from the standpoint of the chemist. 

The term carbohydrates, as it is used, like the term 
protein, is collective and includes a great variety of com- 
pounds. By their common names we know them as sugars, 



70 THE FEEDING OF ANIMALS 

starches, celluloses, gums, and so on. Chemically we dis- 
tinguish them by their structure and by their relation 
to one another. 

90. Classification of carbohydrates according to struc- 
ture. — ^The structure of certain sugars is such that their 
molecules cannot be divided into simpler compounds that 
retain the carbohydrate character, and these are known 
as mono-saccharides. To this class belong glucose (grape- 
sugar) and fructose (fruit-sugar). On the other hand, 
there are a large number of carbohydrates, one molecule 
of which by treatment in certain ways may be converted 
into two or more molecules of a mono- (simple) sugar. 
For instance, one molecule of starch, when submitted to 
the action of an acid or of certain ferments, breaks up 
into several molecules of glucose, and so starch is known 
as a poly-saccharide. Other poly-saccharides are sucrose 
(cane-sugar), maltose (malt-sugar), lactose (milk-sugar), 
cellulose, and the gums, all of which may be split up into 
mono- or simple sugars. The poly-saccharides are sub- 
divided into di, tri, and so on, according as they break up 
into two, three, or more molecules of a simple sugar. 

There are subdivisions of the mono-sugars also, on 
the basis of carbon atoms in their molecules and thus we 
have the names diose, triose, tetrose, pentose, hexose, 
heptose for sugars having two, three, four, five, six, or 
seven carbon atoms in the molecule. It may be remarked 
here that it is among the hexose (six-carbon) sugars or their 
multiples that we find the carbohydrates most important 
to human nutrition. 

91. The mono-saccharides or simple sugars. — ^The 
simple sugars that are most important in animal nutri- 
tion are dextrose (grape-sugar), levulose (fruit-sugar), 
and galactose (from milk-sugar). These are hexose (six- 



CARBOHYDRATES, ACIDS, FATS, OILS 71 

carbon) sugars. The pentoses are also simple sugars, but, 
as we shall see, they scarcely occur in nature, being 
obtained chiefly by splitting up certain gums. 

92. Dextrose. — ^An important simple sugar is dextrose 
or grape-sugar, or what is known in the market as glu- 
cose. Except in the hands of the chemist it is seldom 
seen as crystals, although these appear in the "candying" 
of honey and raisins. It is a constituent of molasses and 
the sirups. Dextrose is found in practically the same 
plants that contain saccharose, such as sorghum, maize, 
and the fruits. So far as known, it is always associated 
with some other sugar. On account of its difficult crystal- 
lization and a lower degree of sweetness, it is less valuable 
for commercial purposes than cane-sugar. That which 
appears in the market is largely made from starch by the 
use of an acid, and it is often utilized for adulterating the 
more costly saccharose. Many seem to regard glucose as 
a substance deleterious to health, but in consideration of 
the fact that, in digestion, starch and most other sugars 
are reduced to this compound before entering the circu- 
lation of the animal, this view does not seem to be sus- 
tained. There is a lack of evidence to show the ill effect 
of glucose either upon man or animals. 

93. Levulose. — ^Another simple sugar is levulose or 
fruit-sugar, the composition of w^hich is identical with 
dextrose, but which has a different chemical constitution. 
It accompanies dextrose and is found in some fruits in 
considerable quantities, and especially in honey. It is as 
sweet as cane-sugar, but does not form crystals with the 
same readiness. 

94. Galactose. — ^This is obtained by a cleavage of 
milk-sugar (see later) into this sugar and dextrose. It 
may also be obtained from certain gums. 



72 THE FEEDING OF ANIMALS 

95. The pentoses. — ^There are several pentoses, none 
of which occurs in nature, but which are prepared by chem- 
ical methods from the gums. Thus, from gum arabic, 
containing araban, arabinose may be obtained, and from 
zylan (wood-gum), zylose may be prepared. Certain of 
these sugars have been isolated from animal compounds. 
They also have been found to appear in human urine. 
They are important in the nutrition of herbivorous 
animals. 

96. Di-saccharides. — These carbohydrates are all 
sugars which may be decomposed into two molecules of 
a simple sugar, or one molecule of each of two simple 
sugars. They are only three in number — saccharose or 
sucrose (cane-sugar), maltose (malt-sugar), and lactose 
(milk-sugar). When acted on by weak acids or cer- 
tain ferments, they break by cleavage (hydrolysis) 
as follows: 

Saccharose+water=dextrose+levulose. 
Maltose H-water=dextrose+ dextrose. 
Lactose -|-water=dextrose+galactose. 

These are the changes that occur during the digestion 
of food. 

97. Saccharose. — ^The most important of these, com- 
mercially considered, is saccharose, which is the ordinary 
crystallized sugar of the markets. As a human food it is 
widely used, is especially valuable, and its manufacture 
and sale constitute a prominent industry. This sugar is 
obtained mostly from two plants, sugar-cane and the 
sugar-beet. It also exists abundantly in sorghum, pine- 
apples, carrots, and in considerable proportions in the 
stalk of ordinary field corn. The first spring flow of sap 
in one species of maple tree is richly charged with it. 



CARBOHYDRATES, ACIDS, FATS, OILS ' 73 

The fruits generally contain saccharose, mixed with 
other sugars and organic acids, and upon the relative 
proportions of these compounds depends the character 
of the fruit as to acidity or sweetness. 

98. Maltose. — ^This sugar is intimately related to the 
first growth which occurs in the germination of seeds. It 
stands as an intermediate product betw^een the store of 
starch in the seed and the new tissues of the sprout. The 
solution that the brewer extracts from the malted grains 
contains this compound as the principal ingredient, and 
through succeeding fermentations in the beer vats it is 
broken up into alcohol and other compounds. It sustains 
an important relation, therefore, to the production of 
beers and other alcoholic liquors. Glucose sirups some- 
times contain small quantities of this sugar. It is also 
found as an intermediary product in the intestinal canal 
during the digestion of food, being derived from starch 
and other carbohydrates through the action of ferments. 
Maltose is similar to cane-sugar in ultimate composition, 
but not in constitution, although as a nutrient it evidently 
has an equivalent value. 

99. Lactose. — The only sugar of animal origin which is 
abundant in farm life is the lactose that is found in milk, 
which is known in commerce as milk-sugar. The milk of 
all mammals contains sugar, which appears to be the same 
compound with every species so far investigated. When 
they are fed wholly from the mother, this is the only 
carbohydrate which young mammals receive in their 
food. The average proportion of sugar in the milk of 
domestic animals varies from three to six parts in a hun- 
dred, cow's milk containing about five parts. \Vhen the 
cream is removed, much the larger part of sugar remains 
in the skimmed milk, and in cheese-making it is nearly all 



74 THE FEEDING OF ANIMALS 

found in the whey, from which the milk-sugar of com- 
merce is obtained. Very soon after milk is drawn, unless 
it is heated to the point of sterilization, or is treated with 
some antiseptic, the lactose begins to diminish in quantity, 
being converted into lactic acid through the action of 
lactic-acid organisms (bacteria). Sour milk, therefore, 
is different from sweet in containing less sugar or none 
at all. 

100. The sugars as a class. — ^When considered from 
the standpoint of eflSciency, the sugars are among the 
most valuable of all the carbohydrates, although in quan- 
tity they are less important than the starches, at least 
in raw food materials. 

Unlike starch, they are found in solution in the sap of 
growing plants. It is probable that these are the forms in 
which carbohydrate material is transferred from one part 
of the plant to another. It is easy to see that some such 
medium of exchange is necessary. The actual production 
of new vegetable substance takes place in the leaves. 
When, therefore, cell-walls and starch grains are to be 
constructed in the stem and fruit, the building-material 
must be carried from the leaves to these parts in forms 
which will readily pass through intervening membranes. 
Excepting certain soluble compounds, closely related to 
starch, the sugars appear to be the only available bodies 
fitted for this office. 

It is very seldom that a plant contains only a single 
sugar. Generally two or more sugars are found together. 
This is especially the case in the corn plant, sorghum, and 
the fruits, and the proportions of each depend somewhat 
on the stage of growth of the plant. 

101. Other more complex poly-saccharides. — ^This 
group includes a large niunber of carbohydrates that may 



CARBOHYDRATES, ACIDS, FATS, OILS - 75 

be considered as complexes of the simple sugars already 
described. Indeed, they make up the principal bulk of 
the carbohydrate-content of cattle foods. These poly- 
saccharides may be divided into three subgroups: the 
starch group, the gum and vegetable mucilage group, and 
the cellulose group. 

102. The starches. — Starch is a widely distributed and 
abundant constitutent of vegetable tissue. Food plants, 
especially those most used by the human family, contain 
it in generous proportions, in some seeds as much as 60 or 
70 per cent being present. Probably only water and cellu- 
lose are more abundant in the vegetable world. 

Starch does not exist in solution in the sap, but is 
found in the interior of plant cells in the foTm of minute 
grains which have a shape, size, and structure character- 
istic of the seed in which they are found. Potato starch 
grains are large, about -roo" inch in diameter, and are kid- 
ney-shaped, while those of the wheat are smaller, about 
■ i 0^0 inch in diameter, and resemble in outline a thick 
burning-glass.' Corn starch grains are angular, being 
somewhat six-sided, and those of other seeds show marked 
and specific characteristics. These differences in size 
and shape furnish the most important means of detecting 
adulterations of one ground grain with another, a method 
much used in the inspection of human and cattle foods. 

Unless modified by some chemical change, starch is 
not dissolved by water. The starch grains are not affected 
at all by cold water, and, in hot water, at first only swell 
and burst. Prolonged treatment with hot water causes a 
chemical change to more soluble substances. For this 
reason the simple leaching of a food material removes no 
starch by solution. At the same time, the cooking of a 
ground grain so breaks up and liberates the starch grains 



76 THE FEEDING OF ANIMALS 

that they are probably acted on more promptly by 
ferments in the digestive fluids. 

The proportion of starch in plant substances varies 
greatly. The dry matter of many seeds, such as rice and 
the cereal grains, wheat, maize, barley, or oats, is largely 
made up of starch. The same is true of potatoes and 
other tubers. Johnson quotes the following figures from 
Dragendorff :* 

Table XXII. Amount of Starch in Dry Matter 

Per cent Per cent 

Wheat kernel .... 68.5 Peas 39.2 

Rye kernel 67. Beans 39.6 

Oat kernel 52.9 Flaxseed 28.4 

Barley kernel .... 65. Potato tubers . . . 62.5 

It appears that in grain plants starch forms most 
abundantly during the later development of the seed. At 
the Maine Station none could be found in very imma- 
ture field corn cut August 15, while on September 21 
the dry matter of the whole plant on which the kernels 
had matured to the hardening stage contained 15.4 per 
cent. In general, the stem and leaves of forage plants are 
poor in starch. 

The distribution of starch in seeds is worthy of note. 
The grain of wheat has been carefully studied in this 
particular, and it is found that this body does not nor- 
mally exist in the seed coatings, this tissue consisting 
largely of mineral matters, proteins, cellulose, and gums. 
On the contrary, the germ and interior material deposited 
around it are rich in starch. To be sure, wheat bran, 
which is now very largely the outer seed coats of the 
grain, has more or less, but this is due to imperfect milling. 

Starch is an important commercial article, and is 

*"How Crops Grow," page 52. 



CARBOHYDRATES, ACIDS, FATS, OILS - 77 

mainly obtained from corn and potatoes. Special forms of 
starch used in cookery are sago, tapioca, and arrowroot. 
It is used as human food, as a source of dextrin, and in 
other ways. By treatment with an acid, corn starch is 
converted into the glucose of our markets, dextrin and 
maltose being intermediate products. 

103. Glycogen. — ^This is the only uncombined carbo- 
hydrate found in the animal body in appreciable quan^ 
tity outside the forms that are in the blood circulation. 
It is sometimes called animal starch. It is a white pow- 
der, soluble in w^ater, and may be extracted in small 
amounts from the muscles and liver. It is formed out of 
the sugars that are taken into the circulation from the 
digestive tract, and, as w^e shall see, is held a reserve store 
of fuel for the maintenance of muscular energy, and in 
this way it performs a very important office in nourishing 
the animal body. (See Par. 214.) It w^as formerly believed 
that another carbohydrate exists in muscle called inosite, 
but it is now known that this substance belongs to a 
different class of compounds. 

104. The pentosans. — ^These bodies are very widely 
distributed in nature, being found in the leaves, stem, 
roots, and seeds of a great variety of plants, in algae and 
in beets and turiiips. Certain pentosans are known as 
gums, such as gum arable, gum tragacanth, and cherry 
gum. Pentosans, on hydrolysis, yield pentose sugars, 
among which are arabinose and zylose. These gum-like 
substances exist in beets and turnips and probably in all 
herbaceous plants that serve as cattle foods. 

105. Galactans, mannans, levulans, dextrans. — ^These 
are compounds of some importance that are more or less 
associated in the framework of a great variety of plants 
or parts of plants, including seeds, beets and turnips. 



78 THE FEEDING OF ANIMALS 

tubers and bulbs, algae, lichens, molds, and the wood and 
bark of many species of trees. On hydrolysis they yield 
galactose, mannose, levulose, and dextrose respectively. 
The compounds are designated as hemi-celluloses. 

They make up the least valuable part of certain vege- 
table foods. 

106. The pectin bodies. — ^Another class of compounds 
much like the gums and perhaps related to them chemi- 
cally, is the pectin bodies. Some of these substances are 
gelatinous in appearance. The jellying of fruits, such as 
apples and currants, is made possible by their presence. 
They exist in greater abundance in unripe fruit than in 
the ripe, consequently the former is selected for jelly- 
making. When such fruits are cooked, the pectin which 
they contain takes up water chemically and is transformed 
into a gelatinous substance known as pectose. Mucilages 
not greatly unlike the gums and pectins exist in certain 
seeds and roots, the most notable instance being flaxseed. 

107. Dextrin, which is sometimes spoken of as a gum, 
is made by heating starch to about 200° C. It may also 
be produced by treating starch with a dilute acid. Dex- 
trin is formed on the outer part of the loaf when wheat 
bread is baked. It is soluble in water. 

108. Cellulose. — ^This is found in the tough or woody 
portion of plant tissue. In tables of food analyses we 
find the term crude fiber, which consists largely of cellu- 
lose, a familiar example of which in a nearly pure form is 
the cotton fiber used in making cloth. Crude fiber is 
separated from associated compounds by the successive 
treatment of vegetable substance with weak acids and 
alkalies, and as so determined is sometimes improperly 
taken to represent the amount of cellulose in a plant. 
While crude fiber is mainly cellulose, it contains a small 



CARBOHYDRATES, ACIDS, FATS, OILS 79 

proportion of other compounds, and besides, more or less 
cellulose is dissolved by the acid and alkali treatment, 
so that the percentages of crude fiber given in food tables 
only approximately measure the cellulose present. 

All plant tissue is made up of cells, the walls of which 
are chiefly or wholly cellulose. It is this substance out of 
which is built the framework of the plant, and which 
gives toughness and rigidity to certain of its parts. The 
more of this plant tissue contains, the more tenacious it 
is, other things being equal, and the more difficult of 
mastication. 

The proportions of cellulose in the different parts of a 
plant are greatly unlike. It is usually most abundant in 
the stem, with less in the foliage and least in the fruit. 
With vegetables like potatoes and turnips, the leaves are 
much richer in fiber than the tubers or roots, which con- 
tain a comparatively smaU proportion. Of the grains or 
seeds, considerable is present in the outer coatings, while 
but little is found in the interior. Vegetables such as 
celery, lettuce, beets, and turnips are relatively rich in 
crude fiber, while tubers, flours, and meals contain only 
small amounts. In certain by-products from the grains, 
like bran, which is made up mostly of the seed coatings, 
fiber is present in fairly large proportions, while in fiour 
derived from the inner parts of the grain, the percentage 
is almost negligible. 

The stage of growth at which a plant is used for food 
purposes has a marked influence upon the proportion of 
crude fiber. In young, actively growing vegetable tissue, 
the cell-walls are thin, but, as the plant increases in age, 
these thicken chiefly through the deposition of cellulose. 
In general, the toughness and hardness of mature plants, 
as compared with young are due to the increased pro- 



80 THE FEEDING OF ANIMALS 

portion of woody fiber, although the decrease in the 
relative amount of water in the tissues and the deposition 
of other substances have more or less effect. 

109. The acids. — Other substances besides those of a 
carbohydrate character are included in the nitrogen- 
free extract. Chief among these are the organic acids, 
compounds which are found mostly in the fruits, although 
they appear in certain fermented products, such as silage 
and sour milk. The most important and well known of 
these are acetic acid, found in vinegar, citric acid in 
lemons, lactic acid in sour milk, malic acid in many 
fruits, such as currants and apples, and oxalic acid in 
rhubarb. Sometimes these acids are free, that is, not 
combined with any other compound. In the main they 
are imited with lime or some other base, forming an 
acid salt. Excepting the fruits, only fermented foods 
contain acids to an appreciable extent. When milk sours, 
the sugar in it is changed to lactic acid under the influence 
of a ferment. The acids of silage are formed at the expense 
of the carbohydrates that are in the material which is 
subjected to fermentation. 

110. Fats and oils. — ^When any finely ground food- 
stuff, either vegetable or animal, is submitted to the 
leaching action of ether, chloroform, or certain other 
solvents, several compounds are taken into solution, the 
main and important ones being fats or oils. These bodies 
make up the chief portion of such an extract from seeds, 
while the extract from other vegetable materials also 
contains a considerable amount of wax, chlorophyl, and 
other substances. Tables that show the composition of 
foods have a column which is sometimes designated 
"ether-extract," and sometimes "fats or oils." The former 
is the more accurate term, because the compounds which 



CARBOHYDRATES, ACIDS, FATS, OILS 81 

it is the intention to describe are often no more than half 
fats or oils. The real value of the ether-extract from 
different foods is partly determined, therefore, by its 
source. When it is all oil, or nearly so, it is worth much 
more for use by the animals than when it is made up to 
quite an extent of other compounds. 

111. Fats or oils in grains and seeds. — ^The propor- 
tions of fat or oil in cattle foods vary within wide limits. 
In general, seeds and their by-products contain more than 
the stem and leaves, the differences in the percentages of 
actual oil being greater than is indicated by the ether- 
extract. But little is found in the dry matter of roots 
and tubers. Among the cereal grains and other more 
common farm seeds, corn and oats show the largest 
amounts, the proportion in dry matter being from 5 to 6 
per cent, while wheat, barley, rye, peas, and rice contain 
much smaller percentages, wheat having about 2 per 
cent, and rice sometimes not over one-fifth of 1 per cent. 
Agricultural seeds that are especially oleaginous are 
cottonseed, flaxseed, sunflower seeds, and the seeds of 
many species belonging to the mustard family, such as 
rape. Peanuts, coconuts, and palm nuts are also very 
rich in oil. The average percentages in these seeds and 
nuts are approximately as given below: 

Table XXIII. Oil in Certain Seeds 





Per cent 




Per cent 


Linseed .... 


34 


Peanuts . . . . 


. . 46 


Cottonseed . . . 


30 


Coconuts . . . 


. . 67 


Sunflower seed . 


32 


Palm nuts . . . 


. . 49 


Rape seed . . . 


42 


Poppy seed . . 


. . 41 


Mustard seed . . 


32 







The oils from all the above are important commercial 
products, being used in a great variety of ways in human 

F 



82 THE FEEDING OF ANIMALS 

foods and in the arts. In many cases, the refuse from this 
extraction goes back to the farm as food for cattle. This 
is especially true of linseed and cottonseed. 

112. Nature and kinds of fats. — ^The vegetable and 
animal fats and oils may, for convenience' sake, be dis- 
cussed in two divisions, the neutral fats, or glycerides, and 
the fatty acids. The neutral fats are combinations of the 
fatty acids with glycerin. When, for instance, lard is 
treated at a high temperature with the alkalies, potash 
and soda, glycerin is set free, and an alkali takes its place 
in a union with the fatty acids. This is the chemical 
change which occurs in soap-making. There are several 
of these neutral fats, the ones most prominent and impor- 
tant in agriculture being those abundant in butter and 
in the body fats of animals, viz., butyrin, caproin, cap- 
rylin, caprin, laurin, myristin, olein, palmatin, and 
stearin, the last three being the most abundant and impor- 
tant in human foods. But;yTin is a combination of buty- 
ric acid and glycerin, stearin of stearic acid and glycerin, 
and so on. Because these are combinations of three 
molecules of a fatty acid radical with one of glycerin, 
they are sometimes named tri-stearin, tri-palmatin, and 
tri-olein, and so on. Some single fats (glycerides) are 
compounds of two or three fatty acid radicals united with 
glycerin in the same molecule. As glycerin is an alcohol, 
and as combinations of an alcohol and acids are ethers, 
the neutral fats are really ethers (esters), although they 
differ greatly from the common conception of an ether 
which is gained from ethyl ether or the ether of drug-stores. 

113. Physical properties of the fats and oils. — ^These 
individual fats possess greatly unlike physical properties. 
They are all soluble in benzine, chloroform, and ether, 
and insoluble in water. At the ordinary temperature of 



CARBOHYDRATES, ACIDS, FATS, OILS - 83 

a room, some are liquid and some are solid, olein belong- 
ing to the former class, and palmatin and stearin to the 
latter. Butter, lard, and tallow differ in hardness at a 
given temperature, and it may easily be discovered that 
their melting-points are not the same. As the animal 
body fats are in all cases chiefly mixtures of olein, palma- 
tin, and stearin, stearin and palmatin being a solid at 
ordinary temperatures, and olein a liquid at anything 
above the freezing-point, it is evident that the relative 
proportions of these compounds will affect the ease of 
melting and the hardness of the mixtures of which they 
are a part. Stearin melts at 71.7° C. and palmatin at 
62° C. Tallow, having much more stearin than lard and 
less olein, is consequently much more solid on a hot day. 

The composition and physical properties of the fat 
from a beef animal seem to vary according to the age of 
the animal and the locality of the body from which the 
fat is taken. Fat from an old animal melts at a lower 
temperature than that from a young animal, and the 
same is true of fat taken from the outside of the body as 
compared with that taken from the inside. Fat from 
the herbivora is in general harder than that from the 
carnivora. 

114. Milk -fat. — ^This contains not only the three 
principal fats, but also the others mentioned, butyrin, 
caprion, caprylin, caprin, laurin, and myristin, in small 
proportions, and these latter tend to give butter certain 
properties that distinguish it from the other animal fats, 
which are almost wholly palmatin, olein, and stearin. 
These special butter-fats are liquid at ordinary tempera- 
tures. Doubtless the flavor, texture, and resistance of 
butter to the effects of heat, are much influenced by the 
proportions of the numerous fats it contains. 



84 



THE FEEDING OF ANIMALS 



115. Fatty acids. — Free, fatty acids exist in nature. 
They are not found in butter, lard, and tallow unless 
these substances have undergone fermentations and 
become rancid. The characteristic flavor of strong butter 
is due to free butyric acid, which, because of fermenta- 
tions, has parted from the glycerin with which it was 
originally combined in the milk. In plant oils, on the 
other hand, are found considerable proportions of the 
free fatty acids, some of which have not been discovered 
so far in animal fats, either free or uncombined. 

116. Ether-extracts. — Stellwaag investigated the in- 
gredients of the ether- and benzine-extracts from plants. 
His results show that not only do these extracts include 
substances which are not fats, but that a considerable 
proportion of free, fatty acids is always present, sometimes 
in quantities exceeding the neutral fats: 



Table XXIV. Composition of Ether-Extracts 



Neutral 


Free fatty 


fats 


acids 


Per cent 


Per cent 


16.3 


56.9 


23. 


35.3 


88.7 


6.7 


73. 


14. 


61.6 


27.6 



Material not 
saponifiable 



Potatoes . . 
Beets . . . 
Maize, kernel 
Barley . . . 
Oats ... 



Per cent 

10.9 

10.7 

3.7 

6.1 

2.4 



It appears, as before stated, that ether-extract, espe- 
cially that from vegetables, may consist, to some extent, of 
materials which should not be classed among the fats. 
The extracts from the grains proved to be nearly all oil. 
Moreover, the grain oils were made up principally of gly- 
cerides, and those from potatoes and beets consisted 
largely of free, fatty acids. 



CARBOHYDRATES, ACIDS, FATS, OILS - 85 

117. Lecithins. — ^These are often called the phos- 
phorized fats. It has previously been stated that neutral 
fats are combinations of fatty acids and glycerin (glycerol). 
Lecithins are compounds in which one of the radicals 
of a fatty acid is replaced by a compound of phosphorus. 
They are widely distributed in nature. They appear to 
be an active component of every cell, both of vegetable 
and animal tissue, and they are especially abundant in 
seeds, in the nerve system, in fish, eggs, and in the yolk 
of eggs. These compounds evidently fill an important 
place in plant and animal nutrition. There are good 
theoretical reasons for suggesting that lecithins serve as 
a stepping-stone to the synthesis of the nucleo-proteins. 
In digestion they behave like the true fats. 

118. Enzjntns, anti-bodies, hormones, vitamines 
(accessories). — ^The science of nutrition must now deal 
with a class of bodies which have not been isolated, some 
of which have merely a theoretical standing, and all of 
which are known chiefly by their reactions. 

Certain of these bodies are formed within the animal 
organism and others are associated with foods. 

The subject of enzjons is treated in Par. 128. 

Anti-bodies are bodies which in some manner neu- 
tralize or hinder the specific action of some other body, 
as for instance the anti-enzyms. It is held that an anti- 
pepsin exists in the mucous membranes of the stomach 
and an anti-trypsin in the mucous membrane of the 
intestine which render these linings immune to the 
action of the digestive juices. 

Hormones, or "chemical messengers" are represented 
by secretin (see Par. 161) which reacts upon certain 
secretory glands, as for instance the pancreas, causing a 
flow of the digestive fluid. The formation of secretin is 



86 THE FEEDING OF ANIMALS 

believed to be due to the reaction of certain food sub- 
stances on the inner membranes of the stomach. 

Vitamines, or food accessories, are regarded as being 
attached to foods, and may properly be styled growth- 
promoting substances. These bodies of an unknown 
nature seem to fall into two classes (Hart and McCollum), 
the fat-soluble accessory attached to butter fat, Qgg yolk 
fat, pig kidney fat, and certain vegetable fats, and a 
water-soluble accessory attached to the wheat embryo, 
^gg yolk, milk-powder, and other foods. These accessories 
are not destroyed by heat, even when subjected to the 
action of steam for two and one-half hours. The fat 
soluble accessory may be concentrated in butter oil by 
fractional crystallization of the harder fats. 



CHAPTER VII 
THE DIGESTION OF FOOD 

We have accepted so far without discussion the almost 
self-evident fact that the food is the immediate source 
of the substance and energy of the animal body. It now 
remains for us to consider the way in which nutrition is 
accomplished. The first step in this direction is the diges- 
tion of food. It is necessary for food ingredients to be 
placed in such relations to the animal organism that they 
are available for use. This involves both condition and 
location. The various nutrients in the exercise of their 
several functions must be generally distributed, and so 
their compounds, in part at least, must be brought into 
soluble and diffusible condition, in order that they may 
pass through the membranous lining which separates the 
blood vessels and other vascular bodies from the cavity 
of the alimentary canal. 

119. Digestion vs. assimilation. — In discussing physio- 
logical relations of food, two terms are employed, viz., 
digestion and assimilation. Digestion refers to the 
preparation of food compounds for use, by rendering 
them soluble and diffusible — changes w^hich are accom- 
plished in what we call the alimentary canal, a passage 
that begins with the mouth, includes the stomach and 
intestines, and ends with the anus. Assimilation signifies 
the appropriation of nutrients, after digestion, to the 
maintenance of the vital processes and to the building 
of flesh and bone — processes taking place in the tissues, 

(87) 



88 THE FEEDING OF ANIMALS 

to which the nutritive substances are conveyed by the 
blood. The two terms are entirely distinct in meaning, 
although they are confused in popular speech. 

120. General changes in food through digestion. — 
In digestion, food imdergoes both mechanical and chemi- 
cal changes. It is masticated, that is, ground into 
finer particles, after which, in its passage along the 
alimentary canal, it comes in contact with several 
juices which profoundly modify it chemically. That 
portion of it which is rendered diffusible is absorbed 
by certain vessels that are embedded in the walls of 
the stomach and intestines, and is conveyed into the 
blood. The insoluble part passes on and is rejected by 
the animal as worthless material, and constitutes part 
of the solid excrement or feces. The forms in which the 
nutrients are conveyed into the circulation are believed 
to be the following: The proteins, previous to absorption 
into the blood, are converted into soluble bodies, at 
first proteoses and peptones, and finally into simpler 
nitrogen compoimds (amino acids) resulting from a more 
extensive cleavage; the carbohydrates enter the blood 
as sugars, chiefly as dextrose. The fats are changed into 
a finely divided form, either as such or as fatty acids and 
soaps. A study of digestion includes, then, a knowledge 
of mastication, of the sources, nature, and functions of 
the several digestive juices, and a consideration of the 
various conditions affecting the extent and rapidity of 
digestive action. 

FERMENTS 

The changes involved in rendering food compounds 
soluble are intimately connected with a class of bodies 




A dairy motlier — Guernsey. 



1^ 




i 




'■' .''" ■'^PlLk^^BI^' 




* '.- ''-^li^ii^iiiiK 


yiiisfPf ' yifl^ 






^z- .■■;' ''^I 


.:• ■.; ^^ >/'>Ci^^4-; 





Well-fed Hereford heifer. 
Plate III. Two good bovine types. 



THE DIGESTION OF FOOD . 89 

known as ferments, and it seems necessary before proceed- 
ing to a consideration of digestion as a process to learn 
something of the natm*e and function of these agents, which 
are actively and essentially present in the digestive tract. 

121. Definition of ferments. — A ferment may be 
defined in a general way as an agent which causes the 
decomposition of certain vegetable or animal compounds 
with which it comes in contact under favorable condi- 
tions. In the past, ferments have been classified into two 
kinds, organized and unorganized. The so-called organ- 
ized ferments are low, microscopic forms of vegetable life, 
generally single-celled plants. The unorganized ferments 
are not living organisms, but are simply chemical 
compounds. 

122. Organized ferments. — ^When milk is allowed to 
remain in a warm room for several hours, it becomes 
sour. An examination of it chemically shows that its 
sugar has in part disappeared and has been replaced by 
an acid. A study of the milk with the microscope, before 
and after souring, reveals the fact that there has been a 
marvelous increase in it of single-celled organisms or 
plants. The presence of this form of life is regarded as 
the cause of the change of the sugar into lactic acid. We 
have here a so-called lactic-acid ferment, which may 
typify the organized ferments know^n as bacteria. Numer- 
ous other fermentations of the same general kind are 
common to everyday experience, such as the changes in 
the cider barrel and the wine cask, the spoiling of canned 
fruits and vegetables, and the heating of hay and grain, 
which are all illustrations of what is accomplished by these 
minute organisms. 

123. Structure and distribution of organized ferments. 
— ^The organized ferments are classed in the vegetable 



90 THE FEEDING OF ANIMALS 

kingdom. As a rule, each individual plant is a single 
cell and so minute as to be invisible to the unaided sight. 
It corresponds in its general structure to the cells which 
make up the tissues of the higher vegetable species, i. e., 
it consists of a cell wall inside of which are protoplasm 
and other forms of matter. These organisms are dis- 
tributed everywhere — in the air, in the soil, on surfaces 
of plants, and in the bodies of animals. Whenever the 
right opportunity offers itself, they multiply and bring 
about all the results attendant upon their growth. 

124. Conditions of growth of organized ferments. — 
The conditions essential to their development are the 
proper degree of moisture and temperature and the neces- 
sary food materials. Animal and vegetable substances 
supply the necessary nutrients, but when thoroughly dry 
do not ferment. Flour and meal that have been dried to 
a water-content of 10 per cent will keep a long time with- 
out loss from fermentative changes. The heat in a mow 
of hay or in a bin of new grain, with their subsequent 
musty condition, is due to the fermentations that are 
made possible through the presence of considerable 
moisture. Thorough drying is a preventive of these 
destructive fermentations. 

There is a temperature at which each vegetable ferment 
thrives best, and there are limits of temperature outside 
of which the growth of these forms of life does not occur, 
or is very slight. Numerous species thrive between 75° and 
100° F. Fermentable materials like fruit and meat at 
the freezing-point or below are not subject to fermenta- 
tions. The boiling-point of water kills most bacteria, 
and temperatures above 150° F. retard or entirely pre- 
vent their growth. 



THE DIGESTION OF FOOD . 91 

125. Results of fermentation. — Like all life, these 
organisms must have food. Many species find this in 
acceptable forms in vegetable and animal products. 
Because these products contain the sugar, proteins, and 
mineral compounds which nourish bacteria, many of 
them are the prey of ferments under proper conditions of 
moisture and temperature. The prevention of fermenta- 
tion in cattle foods is desirable because it occasions a loss 
of nutritive value and often produces undesirable flavors. 
The loss becomes evident when we consider the nature of 
the chemical changes that occur. For instance, when the 
sugars in cider are broken up through the influence of a 
bacterium, carbon dioxid and alcohol are formed through 
the appropriation of free oxygen. This means that com- 
bustion occurs, causing the liberation of energy which 
otherwise would have been available if the sugar had 
been taken as food. Many other fermentations involve 
oxidation, all of which are destructive of food value. 

126. Manner of action of ferments. — ^These little 
plants use sugar and other compounds as food, deriving 
energy and growth therefrom, the carbonic acid, alcohol, 
and other new bodies being the by-products of this use. 
It now appears probable that these organisms develop an 
unorganized ferment which brings about these fermen- 
tative changes. Indeed, it is definitely proved that it is 
possible to. separate from the cells of the yeast plant a 
substance that, in the absence of the yeast plant itself, 
converts sugar into carbon dioxid and alcohol. This 
shows that the effective agent in bacterial fermentations 
is, after all, a chemical substance, or an unorganized 
ferment. These later discoveries tend to remove the dis- 
tinction that has been made between the so-called organ- 
ized and unorganized ferments. Certain ferments are 



92 THE FEEDING OF ANIMALS 

among the most useful agencies with which we deal and 
some are harmful. The yeast plant is useful in bread- 
making, but the putrefaction of meats under the influence 
of another ferment causes loss. 

127. Bacteria in the digestive tract. — ^The digestive 
tract of animals is inhabited by countless numbers of 
bacteria. These inliabit both the stomach and the intes- 
tines, especially the colon. They also form a part of the 
feces. The two main types in which we are interested in 
their relation to digestion are (1) the fermentative or those 
that attack the carbohydrates, especially the sugars, and 
(2) the putrefactive, or those that cause decomposition of 
the proteins. Under certain conditions such as a sudden 
change of food to large amounts of young and succulent 
herbage, especially the legumes, bacterial fermentations 
may endanger the life of the animal through the exces- 
sive formation of acids and gases. 

128. Unorganized ferments. — There is another class of 
ferments which is termed unorganized, and to which the 
general term "enzym'* is given. These are the ferments 
especially important in digestion. They are merely chemi- 
cal compounds, formed within the living cells of the 
plant or animal, which produce a peculiar effect upon 
certain bodies with which they come in contact. If a 
thin piece of lean beef be suspended in an extract from 
the mucous lining of a pig*s stomach, to which has been 
added a small proportion of hydrochloric acid, the liquid 
being kept at about 98° F., the beef will soon begin to 
soften, afterwards swell to a more or less jelly-like con- 
dition, and finally dissolve. The same general result 
would occur with fish, blood fibrin, or the coagulated 
white of an egg. When starch is placed in a warm-water 
solution of crushed malt, it soon dissolves, leaving a com- 



THE DIGESTION OF FOOD - 93 

paratively clear liquid. A chemical examination of these 
preparations will reveal the fact that the compomids of 
the meat are present in solution in somewhat modified 
forms, and that the starch has been changed to a sugar 
or other soluble bodies. In both cases substances insolu- 
ble in water have become soluble and diffusible. 

129. Enz3mis and their action. — ^The cause of these 
changes is the presence, one in the pig's stomach and one 
in the malt, of ferments of the enzym class, the former of 
which renders proteins soluble, the latter producing a 
similar result with the msoluble carbohydrates. This 
action is not entirely like that caused by the presence of 
the organized ferments, where oxidation occurs in many 
cases. The enzyms simply induce the proteins and starch 
to take up the elements of water, a change which is termed 
hydrolysis. How this is done cannot be explained in 
simple terms, if at all. Our knowledge of the manner of 
the change rests to some extent upon theoretical grounds. 
Enz\Tiis are regarded as catalyzers, that is, compounds 
which by their presence cause chemical changes while 
they themselves do not enter into the combinations 
formed. A small quantity of an enz^in may cause changes 
in a large amount of material, the enzym itself under- 
going no appreciable change. The digestion of food is 
largely accomplished through the specific effect of enz^^ms, 
of which every digestive fluid contains one or more. Exam- 
ples of these are the pepsin and pancreatin of the drug- 
store that contain enzjTus mixed with more or less of 
impurities. The various enyzms are often given names 
according to their function: invertase, which in\^erts or 
splits sucrose; glucase, that changes any carbohydrate 
into glucose (also called maltase); lactase, that spHts lac- 
tose into simpler sugars. In general, the ferments acting 



94 THE FEEDING OF ANIMALS 

on starch are called diastases. Enzyms that split fats are 
designated as lipases and those acting on proteins to pro- 
duce proteoses are designated as proteases. 

THE ALIMENTARY CANAL 

The digestion of food is accomplished in the alimen- 
tary canal, a duct that extends from the mouth to the 
anus. 

130. Parts of the alimentary canal. — ^The succession of 
the various parts of this canal is as follows: the esophagus, 
stomach, small intestine (duodenum) and the large intes- 
tine (colon). 

The length of the intestines in the several species of 
farm animals is very great as compared with the length 
of the body of the animal, as the following figures show : 

Sheep, ratio length of intestiae to length of body . 26 times 

Ox, ratio length of intestine to length of body . . 20 times 

Horse, ratio length of intestine to length of body . 12 times 

Dog, ratio length of intestine to length of body . 3 times 

The food is pushed along the intestinal canal by a 
muscular movement of the walls of the intestines known 
as peristalsis, which passes from stomach to rectum, being 
slower in the large intestine than in the small. During this 
passage there occurs both the digestion of food and the 
absorption through the walls of the canal of the digested 
materials. 

THE MOUTH 

131. Mastication. — ^The first step in the digestion of 
fodders and whole grains is to reduce them to a much 
finer condition. This is done in the mouth, the teeth being 
the grinding-tools.* Sometimes the cutting or grinding is 

*This is not true of hens, turkeys, and other fowls. 



THE DIGESTION OF FOOD ' 95 

partially or wholly performed for the animal in hay- 
cutters and grain mills. This mastication is essential for 
two reasons: (1) It puts the food in condition to be swal- 
lowed, and (2) fits it for the prompt and efficient action 
of the several digestive fluids. Dry whole hay or kernels 
of grain could hardly be forced down the tube leading to 
the animal's stomach. It is necessary for these mate- 
rials to be broken down and moistened in order that they 
may be swallowed. Even if they could be conveyed to the 
stomach in their natural condition the process of render- 
ing their constituents soluble would proceed very slowly. 
The more finely any solid is groimd, the larger is the sur- 
face exposed to the attack of the dissolving liquid and 
the more rapid the action. 

132. The teeth. — Prompt and rapid solution of food 
is essential, because, if it is too long delayed, uncomforta- 
ble and injurious fermentations are likely to set in, and, 
because of imperfect digestion, the final nutritive effect 
of the ration may be diminished. For these reasons, 
animals with diseased teeth, or those that have lost teeth, 
make poor use of their food, and require an unnecessary 
amount to keep them in condition. These conditions 
may often be a cause, especially with horses, of disappoint- 
ing results from an ordinarily sufficient ration. The teeth 
of our domestic animals differ somewhat in number and 
arrangement. Authorities state the following to be the 
usual number: 

Table XXV 

Total Incisors Canines Molars 

Horse 36-40 12 4 24 

Ox 32 8 24 

Sheep and goat 32 8 24 

Pig 44 12 4 28 



96 



THE FEEDING OF ANIMALS 



The incisors or front teeth are those which are used 
for prehension, and by grazing animals for cutting off the 
grass and other herbages. With the ox, sheep, and goat, 
incisors are found only in the lower jaw. These move in 
their sockets and shut against a tough pad on the upper 
jaw. They are constantly being pushed out of their 
sockets and wearing off, and with old animals may be 
so worn away as to leave only the roots. Such animals do 




Fig. 1. Glands secreting saliva in man, — parotid, sublingual, 
submaxillary. 



not graze successfully. With the horse and pig, incisors 
are found in equal numbers in both jaws. 

The molars are the grinding teeth. Those of the horse 
sometimes need filing on the edges in order to prevent 
irritation and soreness of the adjacent tissues. A diseased 



THE DIGESTION OF FOOD ' 97 

molar may also occasion an animal much discomfort and 
cause imperfect mastication. 

133. The saUva. — During mastication there is poured 
into the mouth a liquid called the saliva, which has two 
important functions: (1) It moistens the food, and (2) 
with several species of animals it causes a chemical 
change in certain of the constituents of the food. 

134. Origin of saliva. — The saliva has its origin in 
several secretory-glands that are adjacent to the mouth 
cavity, and from these this liquid is poured into the 
mouth through ducts that open in the cheek and under 
the tongue (Fig. 1). The chief of these glands are located in 
the side of the face, below and somewhat back of the jaws 
and beneath the tongue, and are called respectively the 
parotid, the submaxillary, and the sublingual. Other 
glands of this character are scattered in the cheeks and 
at the base of the tongue. The proportions of these glands 
in the several species of farm animals are as follows: 

Table XXVI 

Horse Ox Sheep Pig Dog 

Parotid .... 78 45 52 81 48 

SubmaxiUary . 17 48 43 16 52 

Sublingual . . 5 7 5 3 

135. Properties and office of saliva. — The saliva is a 
transparent and somewhat slimy liquid, and contains 
generally not less than ninety-nine parts in one hundred 
of water, and one part or less of solid matter. It is alka- 
line in reaction, because of the presence of compounds 
of the alkalies. One important organic compound present 
is mucin. The specific chemical effect exerted by this 
liquid on the food constituents may be illustrated by sub- 
jecting starch to its action. When this is done, the starch 
gradually disappears as such and is replaced by dextrin 

G 



98 THE FEEDING OF ANIMALS 

and maltose, chiefly the latter. The agent which is active 
in causing this change is an enzym (see Par. 128), to 
which the name ptyalin has been given, and which is 
always present in the saliva of man and of some animals. 
It is classed among the diastatic ferments, and has an 
office similar to that of diastase in the germination of 
seeds, viz., the transformation of starch into a sugar. 
With man this change begins in the mouth and continues 
in the stomach until the food becomes so acid that the 
ferment ceases to act, for ptyalin is inactive except in an 
alkaline medium. There is yet no reason for concluding 
that with herbivora the saliva is as important in car- 
bohydrate digestion as with man. Different observers 
differ in opinion as to the diastatic value of saliva with 
farm animals. 

The saliva also moistens the food, which is a most 
important office, for it is a necessary preparation to the 
act of swallowing. The saliva is not the same from the 
different glands, that from the parotid being watery with 
no mucin and that from the other glands being rich in 
mucin and therefore very viscid. The former serves 
chiefly to moisten the food while the latter aids in swal- 
lowing. 

136. Quantity of saliva excreted. — With large rumi- 
nants, the quantity of saliva required is large, as is evi- 
dent when we remember that an ox or cow may consume 
in one day twenty-fom* pounds of very dry hay and grain, 
and that rumination goes on much of the time while the 
animal is not eating. It is estimated that oxen and 
horses secrete from eighty-eight to one hundred and thirt}'« 
two pounds daily, an apparently enormous quantity 
of liquid for organs no larger than the salivary glands 
to supply. The extent and character of the secretion of 



THE DIGESTION OF FOOD ' 99 

saliva seems to be modified by the nature of the food 
offered, dry materials stimulating the parotid gland and 
moist foods only the submaxillary and sublingual. The 
organic constituents of the saliva are the peculiar prod- 
ucts of the secretory activity of the cells of the salivary 
glands, and the water and inorganic salts are regarded 
as the result of cell secretion. 

THE STOMACH 

When the food leaves the mouth, it passes down the 
gullet (esophagus) into the stomach. The only modi- 
fications it has suffered up to this point are its reduction 
to a finer condition and a possible action of the mouth 
ferment upon the starch. After the food is swallowed, 
changes of another kind begin sooner or later. 

Before considering gastric digestion from a chemical 
point of view, we should become acquainted with the 
widely differing structure of the stomachs of the various 
farm animals. Those of the ox and horse are greatly 
unlike. The stomach of the ox, and of all other rumi- 
nants, consists of four divisions or sacs, whereas with 
the horse and pig it is made up of a single sac. 

137. The ruminant stomach. — ^The ruminant stomach 
is really quite a complicated affair, and the way in which 
it disposes of the food is understood only after a careful 
study of details. It has four divisions or sacs : the paunch, 
honeycomb, many-plies, and rennet, or what the physi- 
ologist has named the rumen, reticulum, omasum, and 
abomasum. With the ox these cavities contain on the 
average not far from twenty-five gallons, about nine- 
tenths of this space belonging to the rumen (Fig. 2). 

138. Esophageal groove. — A gutter or canal with 



100 



THE FEEDING OF ANIMALS 



an incomplete wall runs to the reticulum and omasum 
from the entrance of the esophagus into the riunen. It 
communicates both with the rumen and reticulum. The 
interior of this canal is not visible in its passage along the 
inner wall of the reticulum unless the lips with which it 
is provided are separated. 




Fig. 2. Stomach of OX. T, rumen or paunch, showing attachment 
of esophagus; C, reticulum or honeycomb; O, omasum or many-plies; 
A, abomasum or rennet, showing attachment of smaU intestine. 

139. The rumen. — ^The food, especially in its first 
descent from the mouth, passes at first mostly into the 
paunch through a slit in the gullet. This cavity, as stated, 
is very large, and it may properly be considered as an 
immense reservoir for the storage of the bulky materials 
which the ruminants take as food. It is divided into 
four sacs by constriction in its walls caused by strong 
muscular bands. As is the ease with the entire digestive 
canal, the waUs of the paunch are composed of three 
layers of tissue, the middle one being a very thick muscu- 
lar coat, which seems necessary to produce the churning 
movement of the large mass of food. The inner or mucous 



THE DIGESTION OF FOOD - 101 

layer is covered with numerous leaf -like projections, in 
which the blood vessels are freely distributed. During 
its stay in this reservoir, where it is held for remastica- 
tion, the moist food becomes thoroughy softened and 
besides imdergoes a variety of changes, chiefly those due 
to bacterial ferments which probably bring about the 
extensive digestion of the cellulose, estimated at from 60 
to 70 per cent. These fermentations are attended by an 
evolution of gases, which imder ordinary conditions are 
absorbed into the blood current. It may be suggested 
that hoven and the puffing up of the paunch of a 
freshly-killed bovine are due to the partial or total failure 
of the blood to take up these gases. Sometimes unnatural 
and dangerous fermentations set in, induced often by the 
consumption in the spring of a large quantity of easily 
fermentable food such as green clover. This causes hoven, 
and unless the gas pressure is at once relieved by an 
opening the animal often dies, due sometimes to the 
bursting of the rumen. Some authorities claim that 
proteohi:ic and amylol>i:ic changes occur in the rumen 
brought about not by enzjTns secreted by the rumen but 
by those contained in the food. 

140. The reticulum. — A portion of the food reaches 
the reticulum either through the esophageal sht when 
first swallowed, or through a large opening between the 
rumen and the reticulum. That which goes directly to the 
reticulum when swallowed is mostly fluid. The reticulum 
also communicates with the third stomach by an opening. 
This is the smallest division of the stomach, and derives 
its common name from the fact that its interior surface 
is divided by ridges of the mucous membrane into cells 
which bear a close resemblance to a honeycomb. These 
cells, which are several-sided and quite deep, appear to 



102 THE FEEDING OF ANIMALS 

be a "catch-all" for the foreign bodies which animals are 
liable to swallow, such as small stones, pins, and nails. 
The contents of this compartment of the stomach are very 
watery, and by being forced into the esophagus and 
rumen appears to aid the return of the food to the mouth, 
portion by portion, for remastication. 

141. Rumination. — ^Rumination, which is the re-chew- 
ing of food previously swallowed, is peculiar to bovines, 
sheep, and goats. In the case of these species, the masti- 
cation of coarse fodder is not completed before it is swal- 
lowed the first time, and they have the power of return- 
ing to the mouth the material which has become stored 
in the rumen and reticulum in order that it may be more 
finely ground. This is what is termed "chewing the cud." 
It is an operation which greatly aids digestion by render- 
ing the food mass finer and more susceptible to the action 
of the digestive fluids. Animals fed on grain alone do not 
ruminate. They "lose their cud," a condition popularly 
and erroneously supposed to be fatal to the animal's 
life. The bolus or "cud" of the bovine weighs approxi- 
mately four ounces and requires for its mastication not 
far from one minute, including preparation, transference 
to the mouth, and return. It is essential to rumination 
that the supply of liquid to the rumen be abundant, to 
which the salivary glands contribute a large share. 

142. The omasum. — After remastication, the food 
does not return wholly to the first and second stomachs, 
but is mostly carried along the esophageal groove to the 
third stomach, the omasum. The finer portions may even 
do this when first swallowed. The omasum is a cavity 
somewhat larger than the reticulum, which has a most 
curious interior structure. It is filled with extensions of the 
mucous membrane in the form of leaves, between which 



THE DIGESTION OF FOOD . 103 

the food passes in thin sheets, an arrangement which 
seems to have for its pm'pose the fm-ther grinding of the 
food so that when it finally reaches the fom*th and last 
compartment it is in a very finely divided condition and 
is thoroughly prepared for the action of the juices that 
are subsequently poured upon it. 

143. The abomasum. — It is at the last stage of the 
journey of the food through this complicated stomach 
that it is submitted to the true gastric digestion. As a 
matter of fact, the abomasum, or rennet, is regarded as the 
true stomach, the other three sacs being considered as 
enlargements of the esophagus. In the calf, the rennet is 
only partly developed, the other divisions not coming into 
use until the animal takes coarse foods in considerable 
quantity. The fourth stomach is larger than either the 
second or third. It receives directly from the omasum 
the finely divided food, upon which it pours the gastric 
juice, a liquid that is secreted in large quantity by glands 
located in its inner or mucous membrane. 

144. The gastric juice. — ^This juice, like all the diges- 
tive fluids, is mostly water, the proportion being between 
ninety-eight and ninety-nine parts to less than two parts 
of various compounds. The latter consist of ferments, a 
certain amount of free hydrochloric acid and a variety of 
mineral compounds, prominent among which are calcium 
and magnesium phosphates and the chlorides of the 
alkalies, sodium chloride being especially abundant. 

145. Artificial digestion. — Especial interest pertains 
to the ferments of the gastric juice, one of which, in con- 
nection with free hydrochloric acid, causes a most impor- 
tant change in the proteins of the food by reducing them 
through hydrol>i:ic and other cleavages to soluble forms. 
We know quite definitely about this action, because it can 



104 THE FEEDING OF ANIMALS 

be very successfully produced in an artijScially prepared 
liquid. If the mucous lining of a pig's stomach, after 
carefully cleaning without washing with water, is warmed 
for some hours in a very dilute solution of hydrochloric 
acid, an extract is obtained which has the powder of dis- 
solving lean meat, wheat gluten, and other proteins. The 
active agent in causing this solution is pepsin, an unor- 
ganized ferment or enzym (see Par. 128) which is present 
in the gastric fluid of all animals. 

146. Changes in stomach digestion. — ^This juice 
changes proteins to peptones, bodies soluble and diffusible. 
The change to peptones is not a single step, for the pro- 
tein passes through successive stages as acid proteins and 
proteoses before it reaches the peptone form. This is 
largely what may be styled progressive hydrolysis. An- 
other ferment present in the gastric juice is the one which 
gives to rennet its value as a means of coagulating the 
casein of milk in cheese-making, and is called rennin. The 
action of this latter body is especially prominent in the 
stomach of the calf when fed exclusively on milk, and it 
is the calf's active stomach, the fom'th in the mature 
animal, which is the source of commercial rennet. Lipase, 
an enzym that acts in the fats, is also possibly present 
in the gastric juice of herbivorse. (See Par. 129.) 

147. Hydrochloric acid essential in stomach diges- 
tion. — ^The free hydrochloric acid in the gastric juice is 
also actively concerned in protein digestion. It is found 
that a solution of pepsin has a limited effect in the absence 
of free acid, for when, during artificial digestion, the 
supply of this acid is used up, it must be renewed or 
digestion is checked. 

148. The stomachs of the horse and pig. — ^These con- 
sist of a single sac, so that digestion with these animals is 



THE DIGESTION OF FOOD 



105 



a much simpler matter mechanically than with rmninants. 
Chemically, the results are essentially similar, i. e., the 
protein is in part changed to peptones. The food, after 
being swallowed, is not retiu-ned to the mouth, but is 
very soon brought under the 
action of the gastric juice with- 
out so long-continued preliminary 
preparation by remastication and 
trituration. For this reason the 
horse fails to digest coarse fodders 
so completely as the ox does. 
Besides, the stomachs of the horse 
and pig are too small to admit of 
so large an ingestion of hay of 
similar material, as is the case 
with ruminants of similar size. In 
all species, however, the chemical 
result of stomach digestion is 
essentially the same, i. e., the protein is in part changed 
to peptones. (Fig. 3.) 




Fig. 3. Stomach of 
horse. B, esophageal at- 
tachment; A, pyloric end 
of stomach, with beginning 
of small intestine. 



THE INTESTINES 



The most extended portion of the alimentary canal, 
though not the most capacious in all cases, is the intes- 
tines. They consist of a tube differing in size in its vari- 
ous portions, which begins with the stomach and ends 
with the anus. 

149. Form and length of intestines. — ^This tube is 
not a straight passage between the points named, but 
presents curves and folds, so that when straightened out 
it appears surprisingly long. Its average length with the 
ox is given as 187 feet, sheep 107 feet, horse 98 feet, and 



106 THE FEEDING OF ANIMALS 

hog 77 feet, lengths which are from twelve to twenty-six 
times that of the bod}^ of the animal. The intestines are 
divided into large and small, the latter being from three 
to fom* times as long as the former. 

150. Food in the small intestine. — ^When the food 
leaves the stomach, it enters the small intestine. At this 
point it is only partially digested. The fats are probably 
so far mostly michanged and, without doubt, the larger 
proportion of the proteins and carbohydrates that are 
susceptible of digestion is still in the original condition. 
Hardly has this partially dissolved material passed into 
the small intestines before it comes in contact with two 
new liquids which are poured on it simultaneously or 
nearly so, viz., the bile and the pancreatic juice, and the 
changes which began in the mouth and stomach, with 
others which set in for the first time, proceed vigorously. 

151. The bile. — ^The bile has its source in the liver. It 
is a secretion of this organ, and after elaboration a reserve 
is stored, until required, in a small sac attached to the 
liver which is called the "gall bladder.'* Gall is conveyed 
to the intestines through a duct opening very near the 
orifice leading out of the stomach. The rate of secretion 
of bile, according to experiments by Colin, is as follows: 
Horse, eight to ten ounces an hour; ox, three to four 
ounces an hour; sheep, one-fourth to five ounces an 
hour; pig, two to five ounces an hour. The secretion and 
flow of bile are continuous but the flow is not uniform. 
Bile is a liquid varying when fresh from a golden red color 
in man to a grass-green or olive-green in certain herbiv- 
orous animals. It is alkaline, bitter to the taste and 
without odor. The specific and characteristic constitu- 
ents of the bile are two acids, glycocholic and tauro- 
cholic, that are combined with sodium and are associated 



THE DIGESTION OF FOOD - 107 

with two coloring matters, bilirubin and biliverdin. 
Numerous other compounds are present in very small 
proportions, such as fats, soaps, and mineral compounds, 
but they appear to have no important relation to diges- 
tion. If any ferment is present at all, it is only as a trace, 
and therefore the bile is incapable of effecting decomposi- 
tions of the proteins and carbohydrates, such as occur in 
the mouth and stomach. 

152. Function of bile. — Nevertheless, this liquid must 
be regarded as having an important function, which it 
exerts in two ways, (1) by preparing the chyme (partially 
digested food from the stomach) for the action of the 
pancreatic juice and (2) it acts in conjunction with the 
pancreatic juice in preparing the fats for absorption. 

Pepsin, the stomach ferment, acts upon proteins only 
in an acid medium. The opposite is true of the ferments 
which the food meets in the intestines, for these require 
an alkaline medium. The bile neutralizes the acidity of 
the chyme, and so prepares the way for the pancreatic 
juice to do its work. It is shown that when the entrance 
of the bile into the intestines is prevented the fat of the 
food largely passes off in the feces. 

Bile has very little, if any, direct digestive action, but 
it may be said to cooperate with the pancreatic juice 
in accomplishing the digestion of fats. It emulsifies fats, 
especially in the presence of the pancreatic juice. When 
the fats are split by a ferment in the pancreatic juice we 
get as a result fatty acids which combine with the alka- 
lies present to form soaps. Both the fatty acids and the 
soaps are dissolved by the bile. In this way the fats are 
prepared for absorption. In experiments by Vail on dogs, 
cutting off the supply of bile reduced the absorption of fat 
from 99 to 40 per cent. 



108 THE FEEDING OF ANIMALS 

It has been asserted that the bile has more or less 
antiseptic influence and so prevents the intestinal con- 
tents from undergoing putrefactive fermentation. A 
more rational explanation is that because the bile acts as 
a natural purgative the food residues pass promptly out 
of the intestinal tract before the putrefactive fermenta- 
tions set in which would occur in the absence of bile. 

153. The pancreatic juice. — This secretion has the 
most comprehensive action on the food nutrients of any 
one of the intestinal liquids. It originates in the pancreas 
(sweetbread). Its flow is intermittent, being induced by 
the reaction especially of the acids in the partially digested 
foods from the stomach. The amount secreted and 
its composition appear to change with the kind of food. 
It contains with the horse about 98.2 per cent of water 
and 1.8 per cent of solid matter. With the dog the per- 
centage of water is about 90. This secretion acts upon all 
classes of nutrients, as it contains a variety of ferments 
greatly unlike in function. 

154. The enzyms of the pancreatic juice. — ^The three 
enzyms present in the pancreas secretion are: a protein- 
splitting enzym, trypsin (or its progenitor), a starch- 
splitting enzym, amylopsin, and a fat-splitting enzym, 
steapsin. Trypsin, like pepsin, hydrolizes the protein by 
progressive stages to proteoses, then peptones, after 
which, in conduction with erepsin (see later), breaks the 
peptones into simpler bodies known as the amino acids. 
(See Par. 84.) Trypsin acts in neutral or in alkaline solu- 
tions, a free mineral acid like hydrochloric completely 
stopping its operation. Organic acids, like lactic, do not 
seem to have this effect. 

155. Steapsin. — ^The pancreatic secretion acts vigor- 
ously on fats, not only splitting them into fatty acids and 



THE DIGESTION OF FOOD - 109 

glycerin, but, in conjunction with the bile, also effects 
their emulsification, this latter result being aided, doubt- 
less, by the soaps which are formed from a union of the 
fatty acids and the alkaline bases (mostly sodium) in 
the bile. The cleavage of the fats is due to an enz;)TQ to 
which the name of steapsin is given, also called "lipase." 
(See Par. 128.) 

156. Amylopsin. — We have seen that starch is acted 
upon to a small extent by the saliva, and that this action 
is not prolonged in the stomach beyond the time when the 
stomach contents become fully acidified. Starch diges- 
tion is therefore carried on mainly in the intestines, 
chiefly, if not wholly, by a diastatic ferment in the pan- 
creatic juice which has the power of hydrolyzing the 
starch mostly into maltose. This pancreatic diastase, 
called amyloysin by some authors, is not found in the 
digestive tract of young animals as abundantly during 
the period of milk-feeding as after vegetable foods are 
taken, for milk does not require the action of a diastatic 
ferment. The presence of bile is very favorable to the 
action of amylopsin. (See Par. 128.) 

157. Intestinal juices. — ^Mention has been made of 
juices that are secreted by small glands distributed in 
the walls of the small intestine. These are quite impor- 
tant factors in digestion, as they supplement the action 
of the ferments of the pancreatic juice. It appears to be 
shown that an enz^m, erepsin, is found in these juices 
that is unable to act upon any of the native proteins 
except casein, but has the power of decomposing proteoses 
and peptones into simpler compounds, particularly the 
amino-acids. These secretions contain, also, the ferments 
that hydrolize sucrose, maltose, and lactose into dextrose. 
It is held also that trypsin does not exist as such in the 



110 THE FEEDING OF ANIMALS 

pancreatic juice when poured into the small intestine, but 
that this enzym is formed from a mother substance in the 
pancreatic juice (trypsinogen) after it comes in contact 
with the intestinal juice, this result being accomplished 
through the action of a body probably secreted from 
the intestinal walls and called by Pawlow "enterokinase." 
(See Par. 154.) 

158. Intestinal bacteria. — So far, in presenting the 
relation of ferments to digestion, only the unorganized 
ferments or enzyms have been considered. While these 
are chiefly concerned in normal digestion, organized 
ferments are present throughout the entire intestinal 
canal and play a part in food changes. They are very 
abundant and active in the rumen and large intestine. 
They act upon the proteins, causing putrefaction, dissolve 
cellulose, and cause a decomposition of the carbohydrates. 
The products of these fermentations include, among other 
compounds, indol and skatol, which have the character- 
istic fecal odor, volatile fatty acids, and gases, some of 
which are carbon dioxid, hydrogen, marsh gas and hydro- 
gen sulfide. The evolution of these gases appears to occur 
constantly and normally with farm animals, particularly 
the bovines, the quantity depending somew^hat upon the 
kind of food. (See Par. 127.) 

159. Effects of intestinal fermentations. — ^Under cer- 
tain conditions, fermentations of this character, which 
are in part normal and may be beneficial, proceed so 
far as to be deleterious. Gorging with a very succulent 
food, such as immature clover, after a period of dry 
foods, or anything which retards digestion, such as 
imperfect mastication, excessive eating, and failure of the 
organs secreting the digestive fluids to supply these fluids 
in suflBcient abundance, give these bacteria a better oppor- 



THE DIGESTION OF FOOD 111 

tunity to act on the food residues, and increase their 
effect. Recent results appear to indicate that the syn- 
thetic activities of intestinal bacteria may be a matter of 
some importance in the utilization of amides (Par. 273). 

160. Stimuli to digestion. — ^The gastric juice is not 
constantly poured into the stomach to accumulate there, 
but is secreted as it is needed under the influence of cer- 
tain stimuli. These stimuli may be classed as psychic and 
chemical. Appetizing odors when there is a strong desire 
to eat, and the agreeable taste of food in the mouth of a 
hungry person are important psychic or "nervous" 
influences that promote gastric digestion through stimu- 
lating the secretion of an adequate supply of the digest- 
ing fluid. Other stimuli that may be called chemical 
result from the indirect reaction of certain substances 
upon the secretory glands. With man, meat extracts, 
proteoses, acids, sugars, alcohol, and condiments seem to 
be effective in this way. This stimulus comes later than 
the psychic, but is more prolonged. 

161. Secretins. — ^The more. recent researches indicate 
that the first products of digestion, reacting on the inner 
membranes of the stomach and duodenum, cause the 
formation of substances called secretins that belong to 
the general class of excitants known as hormones, which, 
carried by the blood stream to the cells of secretory glands, 
excite the secretion of the digestive juices. It now seems 
possible that sometime we shall have a definite dietetic 
method of influencing human digestion, at least, other than 
a medicinal, for it appears that certain food compounds 
may stimulate and others retard the activity of digestion. 

162. The psychic factor. — ^The psychic factor is no 
less important. This being so, it is seen how necessary it 
is that eating shall be pleasurable. Satisfaction with the 



112 THE FEEDING OF ANIMALS 

diet, even with an animal, undoubtedly is a determina- 
tive element in good digestion. Moreover, eondimental 
stimulation is a poor makeshift for the effect of a healthy- 
liking for food. There are good reasons for believing that 
psychic stimulation is an important factor in digestion 
with farm animals. Whether the theory of chemical 
stimuli applies to this class of animals is less certain. 

163. Digestion of food as a whole. — ^From what has 
preceded we learn that several liquids and certain organ- 
isms participate in producing the complex changes that 
food undergoes during digestion. Some of these liquids 
have certain common functions, as, for instance, pro- 
teins are acted upon both by the gastric and pancreatic 
juices. Moreover, the various digesting fluids appear to 
act cooperatively. This is made plain by following the 
course of the food changes. 

164. Stomach digestion. — ^After the food has remained 
in the stomach for a certain period of time, it is gradually 
discharged into the small intestine, the rate of discharge 
varying with the kind of food, that is, with the prompt- 
ness and rapidity of digestion, which differs with different 
foods. The progress made up to this point in food trans- 
ference, so far as we have definite knowledge, is chiefly the 
cleavage of the proteins into various stages of hydrolysis, 
the resulting bodies being proteoses and peptones. All 
proteins appear to be acted on in the stomach, but to 
different degrees and probably at different rates. Starch, 
already somewhat dissolved by the saliva, is not further 
acted upon by the stomach enzyms, neither are the solid 
and liquid fats affected to any material extent. Simple 
sugars are not acted upon by the gastric juice, but it seems 
possible that the di-sugars may be split into simple ones 
by the hydrochloric acid. 



THE DIGESTION OF FOOD ^ 113 

165. Digestion in intestines. — It appears, then, that in 
the intestines protein digestion must be completed with 
the cleavage of peptones into the simpler amino acids, 
the larger part of the starch transformed to sugar and the 
digestion of the fats wholly accomplished or mainly so. 
As a matter of fact, the partial solution in the stomach of 
the proteins and the swelling of the undissolved part to a 
gelatinous mass may be considered as a preparation of the 
food for intestinal digestion, for through these changes 
the proteins present a larger surface to the attack of 
trypsin and other intestinal enz;vTns and digestion pro- 
ceeds more promptly than w^ould be the case with the 
freshly ingested food. Moreover, the compounds in the 
chyme, especially the acid, indirectly react on the liver 
and pancreas, and cause an abundant flow of digestive 
fluids from these glands. 

166. Digestive fluids act together. — ^As soon as the 
chyme mixes with the bile and pancreatic juice, the mass 
is changed from an acid to an alkaline condition. This 
seems to be essential to the effective operation of the 
pancreatic ferments. While the pancreatic juice will 
carry on digestion by itself, this is not satisfactory in the 
absence of bile, one reason for this being that when the 
latter is not permitted to enter the small intestine, the 
digestion of fats is very imperfect. It seems essential that 
these two liquids act together. The bile aids in rendering 
the digesting mass alkaline, contributes to the formation 
and solution of the fatty acids and soaps, and in these 
ways promotes the activity of the pancreas enz^ms. 

167. Action of intestinal juices. — ^The juices that flow 
from the small glands in the intestinal walls appear essen- 
tially to supplement the work of the bile and pan- 
creatic juice. In the first place, they probably contain a 

H 



114 THE FEEDING OF ANIMALS 

substance that activates the mother substance of tryp- 
sin; in the second place, they aid in spHtting the pep- 
tones into simpler bodies, and, lastly, they convert cer- 
tain sugars into the final form (dextrose) in which they 
are absorbed into the blood circulation. 

168. Summary of changes in digestion. — If we con- 
sider the digestion of the food compounds by classes, the 
following is a summary of the ways in which they are 
acted upon: pepsin, trypsin, and erepsin secreted by the 
stomach, pancreas, and intestinal glands act on the pro- 
teins; ptyalin in the saliva, amylopsin from the pancreas, 
and lactase, maltase, and sucrase in intestinal secretions 
act on the carbohydrates, and the fats are acted on 
mainly by the lipase of the pancreatic juice. 

The bacteria are not surely known to have necessary 
specific digestive functions, unless it be their solvent action 
on the cellulose. 

It should be observed that the above is a presenta- 
tion of the general scheme of digestion, and takes no 
accoimt of differences between the various species of 
farm animals of which our knowledge is incomplete. 

ABSORPTION OF FOOD 

From the time the food enters the stomach, during 
nearly its entire course along the alimentary canal, there 
is a constant production of soluble compounds, which 
progressively disappear into other channels, so that when 
the anus is reached only a portion of the original dry 
matter is found in the residue. In some way, not wholly 
explainable in all its details, the digested food has been 
absorbed and received into vessels through which it is 
distributed to the various parts of the body. 



THE DIGESTION OF FOOD 



115 



169. Function of lacteals and blood vessels in absorp- 
tion (Figs. 4, 5). — ^A merely casual observation shows us 
that the inner surface of the walls of the small intestine is 
covered by numerous projections, called villi. In these are 
imbedded the minute branches of two systems of vessels. 




'-layer of circular fibres' 
'layer of longitudinal fibres' 



Fig. 4. Cross-section of mucous membrane of small intestine of man, 
showing capillaries and lacteals. (Gerrish.) 

the lacteals, belonging to the so-called lymphatic system, 
and the capillaries, which are minute branches of the 
blood system. The lacteal is in the center of each villus 
and this is surrounded by a network of capillaries. The 
lymphatic vessels lead to a main tube or reservoir, the 
thoracic duct, which extends along the spinal column 



116 



THE FEEDING OF ANIMALS 



and finally enters one of the main blood vessels. Any 
material, therefore taken up by the lacteals ultimately 
reaches the blood. The capillaries all converge to a larger 
blood vessel, known as the portal vein, which enters the 
liver, transferring to that organ whatever material the 
capillaries have absorbed. 

170. Manner of food absorption. — ^The manner in 
which the soluble food is absorbed has been explained in 

part on common physical grounds. 
When two solutions of different densi- 
ties, containing diffusible compoimds, 
are separated by a permeable mem- 
brane, diffusion through this membrane 
from the denser to the lighter liquid 
will always occur. Such a condition 
'^ as this prevails in the intestines, we 
may believe. The intestinal solution, 
the denser one, is separated from a 
less concentrated liquid, the blood, 
which is constantly flowing on the 
other side of a thin dividing mem- 
brane. Under these conditions there 
occurs the passage into the blood of 
certain parts of the digested food. It 
is held that in this way water, soluble 
mineral salts, and sugar pass directly 
into the blood vessels, chiefly from 
the small intestine. 

171. Changes in the walls of the intestinal tract. — 
In the absorption of peptones and fats, at least, forces are 
encountered other than the osmotic transference of sub- 
stances in solution, the operation of which is still more or 
less unexplained. 




Fig. 5. Intestinal 
villus, showing: a, 
epithelium; 6, capil- 
laries; c, lacteal ves- 
sels. 



THE DIGESTION OF FOOD ' 117 

The ingested proteins are changed in the stomach and 
intestines to peptones, and in part, perhaps mainly, to 
amino acids resulting from the cleavage of peptones. The 
fats are split partly, or entirely, into fatty acids and glyc- 
erin, with the subsequent formation of soaps by the union 
of the free acids with alkaline bases. It has been held that 
in the passage of these new compounds through the walls 
of the intestine changes occur of a synthetical character, 
with a partial or total reconstruction of the proteins and 
fats into forms similar to those in the ingested food. This 
view as to the proteins has been modified somewhat by 
the demonstration of the existence of amino acids in the 
blood showing that, if a s;vmthesis of proteins occurs in the 
intestinal w^alls, it is at least not complete. Amino 
acids may exist in the blood even if synthesis occurs in 
the intestinal walls. The rebuilding of fats and their 
transference into the lacteals is regarded as being 
accomplished through the activity of cells lying in the 
mucous lining of the intestine. This seems to be proven. 
It seems, then, that the vital forces residing in these 
cells probably play a part in the transfer of the nutrients 
into the blood circulation, and that this absorption 
can not be explained whoUy on the basis of osmotic 
pressure. 

172. Place of maximum absorption of food. — ^Absorp- 
tion of digested food takes place to a limited extent 
from the stomach of man and the dog, but not from the 
stomach of the herbivora. The main transference of the 
products of digestion into the blood is from the intestines, 
particularly the small intestine. Much of the water that 
passes into the large intestine is absorbed there, together 
with the products of digestion not already absorbed and 
those products that result from bacterial action. 



118 THE FEEDING OF ANIMALS 



THE FECES 



The soluble and insoluble portions of the intestinal 
contents become separated gradually, and the undissolved 
part arrives finally at the last stage of its journey along 
the alimentary canal, and is expelled as the solid excre- 
ment, or feces. 

173. Constituents of feces. — ^The feces is made up of 
the undigested food, residues from the bile and other 
digestive juices, mucus, and more or less of the epithelial 
cells which have become detached from the walls of the 
stomach and intestines. Dead and living bacteria also 
appear to constitute a material portion of the fecal mat- 
ter. These organisms are not taken in with the food to 
any great extent, but are the result of their continuous 
growth in the digestive tract. Small quantities of fer- 
mentation products, particularly indol and skatol, are 
present, which give to the feces its offensive odor. The 
incidental or waste products may properly be considered 
as belonging to the wear and tear of digestion. 

174. The feces not wholly undigested food. — ^The 
ordinary conception of the fecal residue is that it is only 
the part of the food that has resisted the action of the 
digestive fluids, but in fact it is much more than that. Not 
only does it include the various waste products previ- 
ously referred to, but also compounds that have been 
absorbed into the blood circulation and returned to the 
alimentary canal for excretion. It has been shown, for 
instance, that when a phosphorus compound was in- 
jected subcutaneously into a sheep, the phosphorus was 
excreted in the feces in another combination. It is also 
proven that mineral compounds absorbed from the intes- 
tinal tract may afterward appear in the feces. 



THE DIGESTION OF FOOD 119 

The physical condition of the feces is characteristic 
with each species of animals, the differences in consistency 
being due largely to variations in the amount of water 
present. The amount of water in feces depends more 
upon the character of the food eaten than upon the 
amount of water drunk. 

THE RELATION OF THE DIFFERENT FOOD COMPOUNDS TO 
THE DIGESTIVE PROCESSES 

Numerous digestion experiments with a large variety 
of foods have abimdantly established the fact that these 
materials differ greatly in their solubility in the digestive 
juices. This is an important matter, and one which should 
be well understood, for we must consider both the weight 
of the dry matter eaten and its availability in determin- 
ing its nutritive value. Variations in digestibility are 
caused primarily by variations in composition; therefore, 
we must deal fundamentally with the susceptibility of the 
various single constituents of food to the action of the 
several digestive ferments. 

In this connection, we need to pay little attention to 
the mineral compounds that exist in the inorganic form 
in the food. They do not undergo fermentative changes 
in the way that the carbon compounds do, but are brought 
into simple solution either in the water accompanying the 
food, or in the juices with which they come in contact. 

175. Digestibility of the proteins. — ^As has been noted, 
protein is a mixture of nitrogenous compounds. The gluten 
of wheat contains at least five of these bodies, and other 
seeds as many. What is the relative susceptibility of these 
single proteins to the digestive enzyms either as to rapid- 
ity or completeness of change does not appear to be known. 



120 THE FEEDING OF ANIMALS 

Some proteins are pratically all digested by artificial 
methods, and probably are in natural digestion. It is 
known definitely that protein is much more completely 
dissolved from some foods than from others. That of 
milk and meat is practically all digestible, that of some 
grains very largely so, while with the coarse foods quite a 
large proportion escapes solution. Whether this is due to 
differences in the characteristic protein compounds of the 
various foods is not quite determined. The fact that 
highly fibrous materials show the lowest proportion of 
digestible protein suggests as an explanation that the 
nitrogen compounds of plant tissue are so protected by the 
cell-walls that they escape the full action of the digestive 
juices. It is certain, however, that the protein in plant 
tissue is less fully digested than that from milk and 
meat products. 

176. Digestibility of the carbohydrates. — In the case 
of the carbohydrates, our knowledge of the relative sus- 
ceptibility of the individual compounds to enzym action 
is more definite. First of all, the necessary modification 
of the sugars, which are already soluble, is slight, and they 
are wholly digested. In the second place, we have learned 
in two ways that the starches are wholly hydrolized, first 
by submitting them in an artificial way to the action of 
various diastatic ferments, and, second, by discovering 
a complete absence of starch or its products in the normal 
feces. Under normal conditions the unprotected starches, 
like the sugars, are completely digestible. 

177. Starches unlike in rate of digestibiUty. — Digesti- 
bility must be considered, however, from the standpoints 
both of rapidity and of completeness. As to the former 
factor, starches from unlike sources exhibit some remark- 
able differences. Investigations by Stone, who sub- 



THE DIGESTION OF FOOD . 121 

mitted a number of these bodies to the action of several 
diastatic ferments, show that "this variation reaches such 
a degree that, under precisely the same conditions, cer- 
tain of the starches require eighty times as long as others 
for complete solution." The potato starches appear to be 
acted upon much more rapidly than those from the 
cereal grains. 

178. Digestibility of cellulose and gums. — Other car- 
bohydrates, cellulose and hemicelluloses, such as pento- 
sans, galactan mannan, and related bodies, show great 
variations in digestibility according to their source, 
these variations ranging in observations by Swartz from 
to 100 per cent. The extent to which these latter sub- 
stances disappear from the alimentary canal appears 
to be dependent on their susceptibility to attack by 
bacteria. 

179. Digestibility of the fats. — ^The actual extent of 
the digestion and absorption of the fats or oils is also not 
definitely know^n. If we were to accept the figures given 
for ether-extract in tables of digestion coefficients as 
applying to the real fats, we would believe that their 
digestibility varies from less than one-third to the total 
amount. It is unfortunately true that these coefficients 
mean but very little. The ether-extract from some foods 
is only partially fat or oil, as we have seen, and the inac- 
curacy of a digestion trial is still further aggravated by 
the presence in the feces of bile residues and other bodies 
which are soluble in ether, so that the difference between 
the ether-extract in the ingested food and that iu the 
feces does not give accurate information as to what has 
happened to the actual fats. It seems very probable that 
pure vegetable fats and oils and all mixed animal fats are 
quite completely absorbed. 



122 THE FEEDING OF ANIMALS 

The foregoing statements make it plain that when the 
general composition of a food is known, it is possible to 
predict with a good degree of certainty w^hether its per- 
centage of digestibility is high or low. Feeding-stuffs 
with a high percentage of starch and sugar and a small 
percentage of fiber have a relatively high digestibility, as, 
for instance, corn meal, while the coarse foods like timo- 
thy hay and straw, with a high proportion of gums and 
fiber, have a relatively low digestibility. 

FACTORS WHICH MAY INFLUENCE DIGESTION 

Digestion has an important relation to the nutritive 
efficiency of food because only that portion of the food 
that is digested and absorbed can serve the purposes of 
growth and the maintenance of the vital functions. 

180. Meaning of ^^digestibility." — In discussing the 
factors that may influence the digestion of food, it is 
essential to understand clearly what is involved in the 
term digestion as it is used in science and in common 
speech. This term includes at least two elements, com- 
pleteness of solution of the food nutrients and rate of 
digestion. The figures that are given for the digestibil- 
ity of various cattle foods refer to the completeness or 
extent to which the food is dissolved and transferred to 
the circulation. But different foods from which come the 
same proportion of undigested dry matter may differ 
materially in the rate at which they undergo digestive 
changes, and in this sense their digestibility is unlike. 
The ultimate completeness of solution in the digestive 
fluids may not be influenced by the rate at which the 
process goes on. 



CHAPTER VIII 
' CONDITIONS INFLUENCING DIGESTION 

The chemical changes and other phenomena consti- 
tuting digestion, which have been described as occurring 
in the aUmentary canal, are practically outside the con- 
trol of the one who feeds the animals. They proceed in 
accordance with fixed chemical and physiological laws. 
It is, however, within the power of the feeder to so 
manipulate the food or vary the conditions under which 
it is fed that the extent or completeness of digestion is 
modified, and this must be regarded as an important 
matter when we remember that only the digested food 
is useful. 

181. Palatableness. — It is entirely reasonable to 
believe that a thorough relish for food is conducive to 
good digestion. The secretion of the digestive juices is 
not a mechanical process, but is partly under the control 
of the nervous system. With man, at least, the enjoy- 
ment of eating, even its anticipation, stimulates the 
secretory power of the salivary glands and those in the 
mucous lining of the stomach, and it is evident that this 
holds true with animals. Palatableness is, therefore, an 
important factor in successful feeding, for it tends to pro- 
mote a state of \agorous activity on the part of the diges- 
tive organs. The experienced feeder knows well the 
value of stimulating the appetite of his animals by means 
of attractive mixtures. An agreeable flavor or taste adds 
nothing to the energy or building-capacity of a food, but 

(123) 



124 THE FEEDING OF ANIMALS 

it does tend to secure a thorough appropriation of the 
nutrients which enter the ahmentary canal. Without 
doubt, the success of one feeder as compared with the 
failure of another may sometimes be due, in part, to a 
superior manner of presenting a ration to the animal's 
attention and to manipulations that add to the agreeable- 
ness of its flavors. (See Par. 162.) 

182. Influence of quantity of ration. — ^Early experi- 
ments by Wolff, in which he fed larger and smaller rations 
of the same fodder to the same animals, have been made 
the authority for the statement that a full ration is as 
completely digested as a scanty one, provided the former 
does not pass the normal capacity of the animal. It must 
be said, however, that the testimony concerning this 
point is not unanimous. Since Wolff's experiments, 
Weiske, in feeding oats to rabbits, found the digestibil- 
ity to be inversely as the quantity of food taken. In 
experiments with oxen, by G. Kuhn, at Mockern, when 
the grain ration was doubled the digestibility of the malt 
sprouts used was decreased about 9 per cent. Results 
at the New York Experiment Station from feeding full 
and half rations to four sheep showed uniformly higher 
digestion coefficients with the smaller ration, the differ- 
ences being too large and too constant to be considered 
accidental. Other experiments give varying and con- 
flicting figures. If we assume that the constituents of 
feeding-stuffs have a certain fixed solubility in the 
digestive fluids, then within reasonable limits the amount 
of food should have no effect upon the proportions of 
nutrients digested, but such an assumption cannot safely 
be made. 

Doubtless no single statement concerning this point 
will be found applicable to all animals and all rations. 



CONDITIONS INFLUENCING DIGESTION 125 

Certainly, over-feeding may lessen the extent of solution 
and is never wise, while under-feeding for the sake of 
securing a maximum digestibility would not be good 
practice. It is reasonable to suppose, however, that the 
relation in quantity between the enzyms and the food 
compounds has an influence, at least, upon the rapidity 
of digestion; and indeed investigations by Stone very 
strongly point to such a conclusion, for he fomid that the 
rate of ferment action was proportional to the concentra- 
tion of the ferment solution. 

183. Effect of drying fodders. — At one time the belief 
became very firmly fixed in the public mind that curing 
a fodder causes a material decrease in its digestibility. 
Because this drying is often carried on under conditions 
that admit of destructive fermentations or of a loss of 
the finer parts of the plant, this view is probably correct 
for particular cases; but, if it is accomplished promptly 
and in a way that precludes fermentation or loss of leaves, 
it is doubtful if curing has any material effect upon 
digestibility. 

The point has been the object of six American diges- 
tion experiments, Hungarian grass, timothy, pasture grass, 
corn fodder, crimson clover, and winter vetch being the 
experimental foods. With four of these, slight but unim- 
portant differences were observed in favor of the dried 
material, while the reverse was decidedly true of the 
crimson clover and the corn fodder. German experiments 
show in a majority of cases greater digestibility for the 
green fodders. It seems probable that in general prac- 
tice, because of greater or less unavoidable fermentations 
and a loss of the finer parts of the plant, dried fodders have 
a somewhat low^er rate of digestibility than the original 
green material, a fact not due directly to drying, but to 



126 THE FEEDING OF ANIMALS 

a decrease, either of the more soluble compounds or of 
the tender tissues. (See Par. 306.) 

184. Influence of the conditions and methods of 
preserving fodders. — In comparing the conditions and 
methods of preserving fodders in their relation to digesti- 
bility, we may safely rest upon the general statement 
that when, for any cause, leaching occurs or fermenta- 
tions set in, digestibility is depressed. The explanation 
of this statement is that those compounds of the plant 
which are entirely soluble in the digestive fluids, notably 
the sugars, are the ones wholly or partially removed or 
destroyed by leaching or fermentations, while the more 
insoluble bodies remain unaffected. When, therefore, 
hay is cured under adverse conditions, such as long-con- 
tinued rain, digestibility is decreased, and the same 
effect is inevitable from the changes which occur in a 
fermenting mass, such as a mow of wet hay, a pile of 
corn stalks or the contents of a silo. Experimental 
evidence of the truth of these statements is not wanting. 
German digestion trials with alfalfa and esparsette, 
green, carefully dried, cured in the ordinary way, fer- 
mented after partial drying and as sUage, show a grad- 
ually decreasing digestibility from the first condition to 
the last. A single American experiment, comparing the 
same fodder both green and as silage, gives testimony in 
the same direction. On the other hand, field-cured corn 
fodder, according to nine out of eleven American experi- 
ments, is considerably less digestible than silage coming 
from the same source, although the results of field curing 
vary greatly according to the conditions of exposure. 
Here it is largely a question of the relative loss by fermen- 
tation in the two cases, and it is to be expected that the 
outcome would not be wholly one way. 



CONDITIONS INFLUENCING DIGESTION 127 

185. Influence of the stage of growth of the plant. — 
Another generalization, which certainly must hold good 
with reference to the digestibility of fodder plants, is that 
any conditions of development which favor a relatively 
large proportion of the more soluble carbohydrates, viz., 
starches and sugars, and accompanied by a minimum of 
gums and fiber, promote a high rate of digestibility, and 
reverse conditions produce the opposite result. It is well 
known that, in general, as the meadow grasses mature 
the relative proportion of fiber increases and the tissue 
becomes harder and more resisting. Numerous Ameri- 
can and European digestion trials imite in testifying 
almost unanimously to a gradually diminished digesti- 
bility as the meadow grasses increase in age. The matur- 
ing of maize seems to produce quite the contrary effect. 
The testimony of experiments conducted at the Connec- 
ticut, Maine, and Pennsylvania experiment stations 
justifies the statement that the corn plant, cut when the 
ears are full-grown, furnishes not only a larger amount 
of digestible material, but a larger relative proportion 
than when cut before the ears have formed; and this is 
strictly in harmony with our general principle, for the 
mature plant, on account of the storage of starch in the 
kernels, has by far a larger proportion of the more digesti- 
ble carbohydrates. (See Par. 102.) 

186. Influence of methods of preparation of food. — 
Much labor and expense have been expended by farmers 
in giving to feeding-stuffs special treatment, such as wet- 
ting, steaming, cooking and fermenting, in order to 
secure a supposed increase in nutritive value, an increase 
which must come chiefly, if at all, from a more com- 
plete digestion. It is plainly noticeable that these methods 
of feeding have lost in prevalence rather than gained. 



128 THE FEEDING OF ANIMALS 

Practice does not seem to have permanently ratified 
them, and, so far as digestibihty is concerned, this out- 
come is in accordance with the results of scientific demon- 
stration. The conclusions of German experimenters have 
been that these special treatments have no favorable 
influence, their effect being either imperceptible or 
unfavorable. 

187. Wetting food. — It should occasion no surprise 
that the mere wetting of a food is without influence upon 
its solubility in the digestive juices, because it becomes 
thoroughly moistened during the mastication and in the 
stomach. It is not rational to expect that previous 
wetting would have the slightest effect unless it induced 
more complete mastication, which certainly would not 
be the case with ground grains. The extensive trials by 
Ktihn and others with a hay and bran ration, the bran 
being fed in several conditions, such as dry, wet, moist- 
ened some hours before feeding, treated with boiling water, 
and fermented, gave results adverse to all of the special 
methods of preparation as either useless or harmful, and 
no testimony so thorough and convincing has been fur- 
nished on the other side. 

188. Cooking foods. — German and American experi- 
ments unite in condemning the cooking of foods already 
palatable, because this causes a marked depression of 
the digestibility of the protein, with no compensating 
advantages. Digestion trials with cooked or steamed 
hays, silage, lupine seed, corn meal and w^heat bran, and 
roasted cotton seed, uniformly show their protein to be 
notably less digestible than that in the original materials, 
a fact which may explain the lessened productive value 
of cooked grains which has been observed in certain 
experiments. It must be conceded, of course, that when 



CONDITIONS INFLUENCING DIGESTION 129 

cooking feeding-stuffs by steaming or otherwise renders 
them more palatable, and thereby makes possible the 
consmnption of material otherwise wasted, the influence 
upon digestibility is a minor consideration. 

189. Influence of grinding foods. — ^Few points are 
more frequently questioned than the profitableness of 
grinding grain. There seem to be only two ways in which 
such preparation can enhance the nutritive value of a 
feeding-stuff, viz., by diminishing the energy needed for 
the digestive processes and by increasing the digesti- 
bility. WTiile not many experiments bearing upon the 
digestion side of this question are on record, their evi- 
dence is quite emphatic. In three trials with horses, with 
corn and oats, grinding caused an increase of digesti- 
bility var;v"ing from 3.3 to 14 per cent. A single experi- 
ment with maize kernels gave a greater digestibility of 
about 7 per cent from grinding, and with wheat, in one 
trial, the increase was 10 per cent. In one test with 
sheep, the unground kernels were as completely utilized 
as the ground. It is reasonable to expect that with 
ruminants the danger of imperfect mastication is less 
than with horses and swine, although whole kernels of 
grain are often seen in the feces of bovines. The profita- 
bleness of grinding grain turns, in part at least, upon the 
relation of the cost of grinding to the loss of nutritive 
material from not grinding. If the miller's toll amounts 
to one-tenth the value of the grain the economy of grind- 
ing it may be doubtful, especially with ruminants. The 
utilization of the undigested kernels of grain by pigs is a 
business point to be considered. 

190. Effect of common salt. — It is the custom of 
many feeders to allow their animals an unlimited supply 
of salt, and others furnish it in definite and regular quan- 



130 THE FEEDING OF ANIMALS 

titles. The belief prevails more or less widely that an 
abundant consumption of salt is beneficial. If this is 
true, the advantage arises for other reasons than an 
increased digestibility. The verdict from earlier experi- 
ments by Grouven, Hofmeister, and Weiske that the 
addition of salt to the ration does not increase the digesti- 
bility was confirmed through later tests by Wolff. In- 
deed, if we give to the data collected a literal and per- 
fectly justifiable interpretation, salt diminished rather 
than raised the proportion of digestible nutrients. 

191. Influence of frequency of feeding and watering 
animals. — Experiments relative to this point are not 
numerous. One by Weiske and others, relative to fre- 
quency of feeding, and another by Gabriel and Weiske, 
in which the effects of the time of watering and of the 
amount of water were tested, gave no indication that the 
completeness of digestion is materially affected by varia- 
tions in these details of practice. According to Smith, 
horses should be watered before being fed. He argues 
that water does not stop in the stomach but passes 
directly through it and freshly ingested food would be 
washed into the intestine before any stomach digestion 
occurs, an opinion which tallies with the popular view. 
On the other hand, Tangl asserts, on the basis of extended 
investigations, that horses may be watered either before 
or after eating without depressing digestion, except that 
a horse long deprived of water should be watered before 
eating. The thing chiefly important is that the plan of 
feeding and watering should not be varied. It seems 
probable that the nutritive importance of these minor 
points in managing animals has been much overesti- 
mated by some, especially as affecting the utilization of 
the food. 



CONDITIONS INFLUENCING DIGESTION ' 131 

192. Influence of season and storage. — It is well 

known that the composition of fodder crops grown on the 
same soil may vary somewhat from year to year accord- 
ing as the season is wet or dry, cold or warm. Such varia- 
tions may influence digestibility, though no actual 
demonstration of this fact appears to be on record. The 
question is often asked whether the storage of hay for 
a long period affects its nutritive value. The data from 
four series of experiments touching on this point indicate 
that there is a perceptible, though not marked, decrease 
in digestibility of hay during long-continued storage. 

193. Influence of the combination of food nutrients. — 
Among the apparently important and freely exploited 
conclusions drawn from investigations in animal nutri- 
tion is the statement that the digestibility of food is 
influenced to a marked degree by the relative propor- 
tions of the several classes of nutrients. It is taught that 
if more than a certain percentage of starch and sugar, or 
of feeding-stuffs rich in carbohydrates, like potatoes 
or roots, is added to a basal ration, the digestibility of 
the latter is decreased, the protein and fiber being especi- 
ally affected. The conclusions, as stated by Dietrich and 
Konig, on the basis of a critical study of the data involved 
are that if pure carbohydrates are used to the extent of 
more than 10 per cent of the dry substance of a basal 
ration, or if potatoes and roots are fed equivalent in dry 
matter to more than 15 per cent, a depression of digesti- 
bility occurs, which increases with the amount of carbo- 
hydrate material added. Kellner taught that if the crude 
protein in a ration falls below one part to eight of digesti- 
ble non-nitrogenous nutrients (carbohydrates + fat X 2.25) 
a depression digestibility occurs. It is suggested that 
when much easily digested carbohydrate material is 



132 THE FEEDING OF ANIMALS 

fed the activity of the cellulose digesting bacteria is 
diverted from the crude fiber to the more readily avail- 
able starches or sugars. A modifying conclusion is, that 
if the addition of the carbohydrate material is accom- 
panied by correspondingly more protein, the depression 
of the digestion coefficients is much lessened or does not 
occur. Many data are cited in support of these generali- 
zations which are worthy of careful consideration. 

It is not unreasonable to suppose that the relative 
quantity in a ration of the several classes of nutrients 
may have an influence upon the digestive processes, and 
we should accept the verdict of previous observations in 
so far as they will bear critical discussion and further 
investigation. But it should be said, by way of comment, 
that the carbohydrate material in the experiments cited 
has usually been fed in addition to a basal ration, thus 
increasing the amount of food consumed, and, as we have 
seen, this may have an influence upon the proportion of 
total dry matter digested. In this particular, the experi- 
ments have not been logical. Again, in these experi- 
ments, no allowance has been made for the metabolic 
wastes in the feces, i. e., that material not belonging to 
the true undigested residue. As this appears to be inde- 
pendent of the amount of protein fed and stands more 
nearly in relation to the total digested nutrients, it fol- 
lows that the smaller the proportion of protein in the 
digested food, the larger the error caused in the coeffi- 
cient for protein by the waste nitrogen products. A careful 
study of this point in the light of more recent knowl- 
edge might modify the conclusion reached as to the 
depression of protein digestion through feeding starch 
or starchy foods. In all or nearly all the experiments 
where this effect is apparently shown, the digestible dry 



CONDITIONS INFLUENCING DIGESTION - 133 

matter of the ration was largely increased and the pro- 
tein remained constant or was diminished. However, 
the depression of the digestibility of the crude fiber is 
not easily explained on any other ground than that of 
the influence of the greater proportion of starch. 

What is claimed as the effect of a disproportionate 
addition to the supply of carbohydrates does not appear 
to be true of a similar increase in the ration of fat and 
easily digested protein. Several experiments in which 
oils and albuminoids have been added freely to a basal 
ration did not indicate that such addition had any mate- 
rial effect upon digestibility. 

194. Influence of work. — Such evidence as has been 
secured with both man and farm animal indicates that 
even severe labor has no material influence upon diges- 
tion one way or the other. Scheunert's work with horses 
leads him to conclude, however, that exercise improves 
digestion. 

195. Influence of species, breed, age, and individual- 
ity. — ^The conclusion reached by the early experimenters 
in the field of animal nutrition that the digestive efficiency 
of the several species of ruminants was practically uni- 
form has not been set aside by more recent observations. 
The number of experiments upon which this conclusion 
was based was large, and their verdict is not likely to be 
reversed by observations less extensive or less complete. 

The following coefficients were obtained from German 
trials with meadow hay: 

Dry Substance Digested from Meadow Hay (Per Cent) 

Samples Best Medium Poor 

Sheep 42 67 61 55 

Oxen 10 67 64 56 

Horse . 18 58 50 46 



134 THE FEEDING OF ANIMALS 

In nine American experiments the digestive efficiency 
of large and small ruminants has been studied, steers 
being compared with sheep and cows with goats. In 
five cases, the large animal digested from 5 to 14 per cent 
the more, in three cases the excess for the small animal 
varied between 7 and 17 per cent, and in one case there 
was little difference. The general effect of such conflict- 
ing results is to confirm the older and more numerous 
observations. 

196. Lower digestibility with horses for coarse 
foods. — ^The horse and ruminants differ in digestive 
capacity to a marked extent. The comparisons which 
have been made show a uniformly lower digestive effi- 
ciency for coarse fodders on the part of the former. It 
appears that because of less perfect mastication, or for 
some other reason, the horse dissolves much less of the 
crude fiber than the steer or sheep, and the effect of this 
is prominent with hays and other fibrous materials. 
With the grains, ruminant and equine digestion is not 
greatly unlike, eight samples of oats with sheep and 
twenty-four with the horse showing almost identical 
digestion of the dry matter. With maize the case is the 
same. In experiments with beans, the advantage was 
slightly with the ruminant. The difference between 
bovine and equine digestion is certainly least with highly 
digestible rations containing a minimum of fiber. So 
far as we are able to judge, swine digest concentrated 
food about as do ruminants. How this is in the case of 
fodders we do not know fully, but it is shown that the 
swine digest crude fiber quite freely. 

Past experiments have not revealed any influence of 
breed upon digestive capacity. There is no reason for 
supposing that Shorthorn cattle. Southdown sheep, and 



CONDITIONS INFLUENCING DIGESTION ^ 135 

Chester White pigs would digest rations differently from 
Jerseys, Merinoes, and Yorkshires. 

Young animals seem to digest high-quality coarse 
foods and grains as efficiently as older ones of the same 
species, which is probably contrary to the popular belief. 
There is doubtless a variation in the digestive power of 
individual animals, but the data so far collected do not 
show this with any degree of definiteness. In those in- 
stances where the same four or more steers or sheep have 
been used in determining the digestibility of several 
feeding-stuffs, the highest coefficients were obtained 
sometimes with one animal and sometimes with another. 

197. Determination of digestibility. — If we accept 
as the undigested food the dry matter of the solid excre- 
ment, which is practically in accordance with the fact, we 
have only to subtract the dry fecal residue from the dry 
matter of the ingested food in order to ascertain the 
amount and proportion digested. All digestion experi- 
ments have proceeded on this basis. Animals have been 
fed at regular intervals a uniform quantity of carefully 
analyzed food and the feces have been collected, weighed, 
and analyzed. From the data thus obtained, the digestion 
coefficients have been calculated. The method and the 
mathematics of such experiments are so simple that cor- 
rect results seem very easy to obtain and they do possess 
an accuracy sufficiently approximate to truth to render 
them useful in practice. As digestion trials are usually 
conducted, the coefficients of digestibility obtained for 
the dry matter and total organic matter represent, we 
have reason to believe, very nearly the actual digestible 
matter in the particular material studied. The propor- 
tions secured for particular classes of nutrients may be 
less accurate, for reasons that will appear. We cannot 



136 THE FEEDING OF ANIMALS 

be sure, either, that the digestibihty of one hay appHes 
to another produced and cured under totally differ- 
ent conditions. The truth of this latter statement is 
clearly seen in the effect of the various factors upon 
digestibility. 

198. The inaccuracies of digestion coefficients. — ^The 
inaccuracies of digestion coefficients are in part those 
for protein and fats. The errors in the figures for protein 
are caused by the presence in the feces of nitrogen com- 
pounds which are not a part of the undigested food pro- 
tein. (See Pars. 173, 174.) These are waste compounds 
which are residues from the bile and other digestive juices, 
epithelial cells and mucus which are carried along from 
the walls of the intestines during the passage of the food. 
Their quantity seems not to be proportional to the pro- 
tein fed, but appears to be influenced more or less by the 
amoimt of food digested. Their source is in part the 
"wear and tear" of the digestive apparatus. It follows then 
that the less protein there is in a ration, the larger the 
percentage error caused by these metabolic products. 
In certain experiments with oat straw, the fecal nitrogen 
has been more than that of the food, although without 
question much of the straw protein w^as digested. It has 
been found, using the best methods known for extracting 
these waste products, that they cause a much larger 
error for the protein of the straws than for that of the 
legume hays. Under some conditions, at least, ten should 
be added to the coefficients of digestibility of the protein 
of coarse fodders as usually given in the tables that have 
been compiled. 

Errors are caused in determination of the digestibility 
of fat in much the same way. Certain of the bile residues 
in the solid excrement are soluble in the ether which is 



CONDITIONS INFLUENCING DIGESTION 137 

used to extract the fats and consequently the undigested 
fat appears to be much larger than it really is. 

Reference has been made to the return to the intes- 
tinal tract of material that was absorbed into the circula- 
tion and is in part returned to the intestines for excre- 
tion, as, for instance, the phosphorus of phytin and other 
compounds. Such material is not a part of the undigested 
food residue. 



CHAPTER IX 

THE DISTRIBUTION AND USE OF THE 
DIGESTED FOOD 

The digested food, after absorption, all passes into 
the blood, either directly or indirectly, and mixes with 
it. The materials which are to serve the purposes of 
nutrition are now taken up by a stream of liquid that is 
in constant motion through the minutest divisions of 
every part of the animal. Flowing in regular channels 
the blood reaches not only the bones and muscular tis- 
sues, but it passes through several special organs and 
glands where the nutrients it is carrying and certain of 
its own constituents meet with profound changes. It is 
here that we discover the manner in which food is applied 
to use and what are some of the transformations which 
the proteins, carbohydrates, and fats undergo in perform- 
ing their functions. 

In order to follow intelligently this most interesting 
phase of nutrition, we must know something of the blood 
and of the organs — ^the lungs, liver, and kidneys — ^through 
which it passes. 

199. The blood. — The blood, which makes up from 
3 to 4 per cent of the total weight of the hve animal, 
when in a fresh state, is apparently colored and opaque, 
but if a minute portion is examined with a microscope, it 
is seen to be a comparatively clear liquid in which float 
numerous reddish disk-like bodies. These bodies, which 
are known as corpuscles, give to the blood its bright red 

(138) 



USE OF THE DIGESTED FOOD 



139 



color. The liquid in which they are suspended is called 
the plasma. 

200. The blood corpuscles (Fig. 6). — The corpuscles 
are not mere masses of unformed matter, but they are 
minute bodies having a definite form and structure. They 
make up from 35 to 40 per cent of the blood, and con- 
tain over 30 per 

e 



cent of dry 
matter. This 
dry matter con- 
sists mostly of 
hemoglobin, a 
compound that 
is peculiar to the 
blood and equips 
it for one of its 
most important 
offices. Hemo- 
globin, when 
broken up in the 
absence of oxy- 
gen, is found to 
be made up of a 
protein (globin- 
histone) and a 
coloring matter 
(hemochromogen) in the latter of which is combined a 
definite proportion of iron. When broken up in the pres- 
ence of oxygen we get globin and hematin, as hemo- 
chromogen when oxydized becomes hematin. The peculiar 
property of hemoglobin which renders it so useful a con- 
stituent of the blood is its power of taking up oxygen 
and holding it in a loose combination until it is needed 




Fig. 6. Red and white corpuscles of blood 
(magnified). A, red corpuscles; a, a, white cor- 
puscles; B, C, D, red corpuscles, more highly 
magnified; F, G, white corpuscles, more mag- 
nified. 



140 THE FEEDING OF ANIMALS 

for use. When thus charged, it is known as oxyhemo- 
globin. Because of this function of their most prominent 
constituent, blood corpuscles become the carriers of 
oxygen to all parts of the body. The blood corpuscles 
are also concerned in gathering up one of the waste 
products of metabolism, viz., carbon dioxid, and convey- 
ing it to the point where it may be thrown off from the 
body. (See Par. 77.) 

201. The blood plasma. — ^The plasma is a liquid 
having a very complex composition. It is about nine- 
tenths water, so that it easily holds in solution whatever 
soluble nutrients are discharged into it from the alimen- 
tary canal. Among its constituents are found members of 
all the classes of compounds that are important in this 
connection — ash, protein, carbohydrates, and fats. The 
proportion of ash is about 1 per cent, three-fourths of it 
being common salt, and the remainder consisting of 
phosphoric acid, lime, and other important mineral com- 
pounds. The solid matter of the plasma is rich in pro- 
teins, including the fibrinogen which is the mother sub- 
stance of fibrin and several albumins and globulins. 
These proteins make up about 80 per cent of the total 
dry substance of plasma. Sugar and fats are also present, 
their proportions undoubtedly varying somewhat with 
the extent to which they are being absorbed from the 
digestion of food. It is evident that the blood is charged 
with those materials which we recognize as necessary to 
the construction and maintenance of the animal body. 

202. The heart. — ^The blood is contained in the heart 
and in two sets of vessels, one set called the arteries lead- 
ing from the heart by various ramifications to all parts 
of the body, and the other set called the veins, leading 
from all parts of the body back to the heart. Through 



USE OF THE DIGESTED FOOD 



141 




"-T^ 



O I ti 



142 



THE FEEDING OF ANIMALS 




these vessels the blood is mov- 
ing in a constant stream, which 
we call the circulation. It does 
not move of itself, but is forced 
along by a very powerful pump, 
the heart. This is a highly 
muscular organ divided into 
four chambers, which are sepa- 
rated by valves and partitions, 
the two upper chambers being 
called the right and left auri- 
cles, and the two lower the right 
and left ventricles. The right 
auricle is above the right ventri- 
cle and is separated from it by 
a valve, and the same is true 
of the left auricle and ventricle. 
(Fig. 7.) 

203. Circulation of blood. — 
Out of the left ventricle the 
blood is pumped into the arteries 
and, after reaching the arterial 
capillaries throughout the entire 
body, it passes from these into 
the smallest divisions of the 
veins and comes back to the 
heart along the venous system, 
entering the right auricle. It 
is then carried to the lungs by 



Fig. 8. Diagram of circulation. 1, 
heart; S, lungs; 3, head and upper 
extremities; 4. spleen; 5, intestine; 6, 
kidney; 7, lower extremities; 8, liver. 
(Collins.) 



USE OF THE DIGESTED FOOD * ^ 143 

way of the right ventricle and is returned from the 
lungs to the left auricle to be sent to the left ventricle, 
and from there to again start on its journey through 
the body. (Fig. 8.) 

The nutrients, as prepared for use by digestion, enter 
the blood on its return flow to the heart, coming into 
the venous cavity by way of the hepatic (liver) vein and 
the thoracic duct as previously described. When, there- 
fore, the right side of the heart is reached, a new acces- 
sion of food material is on its way to sustain the various 
functions of nutrition. 

We are more interested in the object of blood circu- 
lation than we are in its mechanism. Somehow the 
digested food disappears into these constantly movmg 
blood currents, and the only evidence of its effect which 
comes to us from ordinary observation is the warmth, 
motion, and perhaps growth of the animal that is 
nourished. 

204. The lungs.— The first point where important 
changes occur is the lungs. Here the blood loses the pur- 
plish hue which it always has after being used in the body 
tissues and takes on a bright scarlet, a phenomenon that 
is more easily explained when we imderstand the lung 
structure. (Fig. 9.) 

Breathing is a matter of common experience. We all 
know how air is drawn into the lungs at regular intervals, 
an equivalent quantity being as regularly forced out. 
The mechanism of respiration (breathing) we will not dis- 
cuss at length. It will aid us, however, if we know that 
the passage which the air follows to and from the lungs, 
the trachea (windpipe), divides into two branches, one to 
each lung, and these divide and sub-divide until they 
branch into numerous fine tubes. Each of these tubes 



144 



THE FEEDING OF ANIMALS 



ends in an elongated dilation which is made up of air 
cells opening into a common cavity. These cells are so 
numerous in the lung tissues that only a very thin wall 
separates adjoining ones, and in this wall are carried the 



UPPER L0BB 



OPPER LQBB 




LEFT UING 



Fig. 9. Air-tubes of the human lung. (Gerrish.) 

capillaries or fine divisions of the blood vessels leading 
from the heart. 

205. Object of respiration. — ^The lung structure per- 
mits the blood to take up ox>^gen as it flows along and 
transfer certain wastes into the lung cavities, and thus be 
made ready to go back to the body carrying a joint load 
of digested food and oxygen. The air that passes out of 



USE OF THE DIGESTED FOOD ' 145 

the lungs is less rich in oxygen than when it was taken in, 
and there have been added to it certain materials which 
are noticed later. 

206. The use of food. — ^The revivified blood now 
passes to all parts of the body and is brought into the 
most intimate relation with the minutest portion of every 
tissue. Several things happen in the course of time. 

In the first place, the new supply of nutritive sub- 
stances is used by the living cells in a way we do not 
wholly understand to rebuild worn-out tissue and to 
form new^ growth. With the young animal, much material 
is appropriated in the latter way. In the case of the milch 
cow, there is furnished to the udder the nutrients out of 
wliich certain constituents of milk are formed through the 
special activities of that gland. 

207. Nutrients are oxidized. — ^Moreover, it is in the 
tissues that the oxy^gen which was taken up in the lungs 
is used to burn slowly a portion of the food. This com- 
bustion does not take place by the mere contact of the 
oxA'gen and food in the large blood vessels, but it occurs 
by progressive steps throughout the minute divisions of 
the muscles and other parts of the whole body. Not- 
withstanding this oxidation may be very gradual and 
occupy much time, its ultimate products are, for the most 
part, similar to those which result from the rapid com- 
bustion of fuel. In the fireplace, starch, sugar, cellulose, 
fats, and similar bodies w^ould be burned to carbonic acid 
and water, and this is what takes place in the animal to 
the extent that these nutrients are not used for the forma- 
tion of body substance. When the protein is not stored 
as such but is broken up, the result differs somew^hat in 
the furnace and in the animal because in the latter the 
oxidation is not complete. 

J 



146 THE FEEDING OF ANIMALS 

208. Oxidases. — The manner of this oxidation is one 
of the difficult physiological problems. The present view, 
and one based on very significant data, is that these 
oxidations of the nutrients is the result of enzym action 
and the oxidizing ferments are designated as oxidases. 
The proteins, carbohydrates, and fats are first acted on 
during digestion by the hydrolizing enzyms, and the 
cleavage products are then further broken down, or 
oxidized, by the oxidases. 

209. Proteins not wholly oxided. — The proteins may 
be partially burned to carbonic acid and water, but unless 
used for tissue formation a portion of their substance 
passes from the body principally in the form of urea and 
uric acid, which are the prominent constituents of urine. 
These compounds carry with them a certain proportion 
of carbon and hydrogen which in ordinary fuel com- 
bustion would more fully unite with oxygen. The heat 
production from protein is therefore less in the animal 
than in the furnace. 

210. Rate of oxidation of nutrients. — ^This oxidation 
in the animal is constant but not uniform. It varies with 
the exercise the animal is taking and with the amount of 
food that must be disposed of. The quantity of oxygen 
needed is therefore variable, and when the demand for it 
is largely increased the heart pumps faster, more blood 
passes through the lungs, the breathing is more rapid and 
the supply of oxygen is in this way augmented. 

ELIMINATION OF WASTES 

The various waste products from this combustion and 
from the breaking up of the proteins within the animal 
evidently must be disposed of in some manner. When 



USE OF THE DIGESTED FOOD ' 147 

not eliminated from the body, they cause results of a 
most serious character, as, for instance, when an accumu- 
lation of urea in the body produces ursemic poisoning. 
The blood therefore not only carries to the tissues the 
necessary nutrients and oxygen, but it has laid upon it 
the burden of taking into its currents the waste products 
of combustion and growth and carrying them to the 
points where they are thrown off. (See Par. 77.) 

211. Elimination of urea. — One of the branches of the 
arterial system of blood vessels runs to the kidneys, and, 
by repeatedly rebranching, traverses all their substance. 
The main function of the kidneys is to eliminate certain 
products through the urine. It is in this way that all the 
waste nitrogen from the digested protein finds its way out 
of the body in the form of urea and similar bodies. The 
blood that enters them carries with it the urea and uric 
acid w^hich have resulted from a breaking down of pro- 
tein, and in a most wonderful manner these compounds 
are filtered out so that they are not present in the out- 
going blood. An excess of soluble mineral matters, espec- 
ially the alkaline salts is also removed by the kidneys, as 
well as the bile compounds which are absorbed from the 
alimentary canal. 

212. Elimination of carbon dioxid. — ^The carbon 
dioxid must in some way also be eliminated from the 
body. This is not accomplished to any extent until the 
blood containing it reaches the lungs, where it is ex- 
changed for a new supply of oxj^gen and passes off in the 
expired air. In the case of man, the air * 'breathed out" 
is nearly a hundred times richer in carbonic acid than the 
air "breathed in." 

213. Elimination of water. — ^Water may be regarded 
from one point of view as a waste, for it is produced in 




Fig. 10. Portal system of veins in the human subject, showing how 
absorbed nutrients are collected from intestinal tract and carried to 
liver by portal vein. 

(148) 



USE OF THE DIGESTED FOOD ' 149 

the oxidation of the food, and this passes off from the 
lungs as vapor, through the skin as sensible or insensible 
perspiration, and in considerable quantities through the 
kidneys. 

To summarize, it may be said that the blood is con- 
stantly undergoing gain and loss. The gain comes from 
the food (including water and oxygen), and the loss con- 
sists of the compounds in the urine, carbonic acid, and 
water given off through various channels. 

THE LIVER 

214. Regulation of carbohydrate use. — One part of 
the arterial system of blood vessels rims to the stomach 
and intestines and is distributed over their walls in fine 
divisions. These connect with the capillaries of the portal 
vein which leads to the liver (Fig. 10). During this passage 
of the blood from one system to the other, part of the 
digested food is taken up. The quantity of material thus 
absorbed must vary greatly at different times according to 
the nature and amount of food supply and the activity of 
the digestive processes. If, therefore, the blood from the 
alimentary canal were allowed to pass directly into the 
general circulation, the supply to the tissues of the sugar 
resulting from digestion would be very uneven. Just here 
comes in a liver function. In that organ there is found a 
starch-like body known as glycogen, which appears in 
increased quantity following the abundant absorption 
of sugar from the intestines. It is believed, because of 
this and other facts, that the liver acts as a regulator of 
the carbohydrate supply to the general tissues of the 
body, storing a temporary excess of the sugar in the form 
of glycogen and then gradually giving it up to the gen- 



150 THE FEEDING OF ANIMALS 

eral circulation as it is needed. Glycogen is also stored in 
the muscles in an amount equal to or greater than in 
the liver. (See Par. 103.) No better illustration can be 
cited of the nicety of adjustment of the animal organism 
to the maintenance of its activities than this regulation 
of its fuel supply to the areas of oxidation. 



/ 



/ 



•-W— ^./^ 



CHAPTER X 

THE FUNCTIONS OF THE NUTRIENTS 

The digestion, absorption, and distribution of food 
are not its use — ^they are the preliminaries necessary to 
use. Not until the nutrients have been converted to 
available forms and have passed into the blood do they 
in the slightest degree furnish energy or building-material 
to the animal organism. We have followed to a certain 
extent the chemical changes which the digested food 
suffers, but no detailed statements have been made as 
to the part taken by each class of nutrients in constructing 
the animal body and in maintaining its complex activities. 

215. General uses of food. — ^Animals use food in two 
general ways, viz., for constructive purposes, which 
involve the building or repair of tissue and the forma- 
tion of milk, and as fuel for supplying different forms 
of energy. The tissues which are to be formed are of 
several kinds, principally the mineral portion of the bone, 
the nitrogenous tissue of the muscles, tendons, skin, hair, 
horn, and various organs and membranes, and the deposits 
of fat which are quite generally distributed throughout 
the body substance. 

216. Uses of energy. — Energy in the forms in which it 
is used by the animal organism may appear as muscular 
activity, both internal and external, such as working, 
walking, breathing, the beating of the heart, the move- 
ments of the stomach and intestines, as heat, and as 
chemical energy necessary for carrying on digestion and 

(151) 



152 THE FEEDING OF ANIMALS 

other metabolic changes. The animal body is certainly 
the seat of greatly varied and complex constructive and 
destructive activities, which are sustained by the matter 
and potential energy of the food. How this is done we 
do not fully understand, but we know many facts which 
are of great scientific and practical importance and which 
the feeder must consciously or unconsciously recognize 
if he would not come into conflict with immutable laws. 
(See Pars. 236-241.) 

217. Functions of water. — ^Water fills an impor- 
tant place in the nutrition of all forms of life. In both 
plants and animals it acts as a solvent of the building- 
materials which it carries from one part of the organism 
to another. It also serves as a carrier of wastes, particu- 
larly those excreted through the kidneys, and the free 
use of water is recommended as promoting thorough 
cleansing of the tissues. It is proper to speak of water 
as building-material for the animal body, for it is an 
abundant constituent of animal tissue and takes part in 
chemical changes such as hydrolysis. It fills an essential 
office in regulating the heat processes of the body through 
varying rates of evaporation from the surface of the body. 

FUNCTIONS OF THE MINERAL ELEMENTS 

218. Relation of mineral elements to vital processes. — 
The life of an animal is maintained through chemical 
reactions between substances in solution. These reactions 
are brought about by means of electrical currents, and 
the importance of the mineral salts in these relations is 
seen in the fact that very dilute solutions of the mineral 
salts in water increase greatly the electrical conductivity. 
The organic compounds in the body have a low electrical 



FUNCTIONS OF THE NUTRIENTS 



153 



conductivity or are inert, and it is the presence of the 
mineral elements in solution carrying electrical charges 
which makes possible the reactions involved in metabolism. 
Without the mineral elements protoplasm w^ould be dead. 
219. Relation of mineral elements to animal struc- 
ture. — ^The mineral elements are largely involved in the 
structure of the animal body. They constitute the entire 
amount of the ash in which the elements calcium and 
phosphorus exist in the largest proportions. The follow- 
ing table illustrates the kinds and distribution of mineral 
elements in the bodies of five species of farm animals. 

Table XXVII 







Ox 


Calf 


Sheep ' 


Lamb 


Pig 




Half 
fat 


Fat 


Fat 


Thin 


Half 
fat 


Fat 


Very- 
fat 


Fat 


Thin 


Fat 


Fat 

Nitrogenoiis 

matter . . . 
Minerals . . . 
Water .... 
Contents of 

stomach, etc. 


Per 
cent 

19.1 

16.6 
4.66 
51.5 

8.2 


Per 
cent 

30.1 

14.5 

3.92 
45.5 

6. 


Per 
cent 

14.8 

15.2 
3.8 
63. 

3.2 


Per 

cent 

18.7 

14.8 

3.16 
57.3 

6. 


Per 
cent 

23.5 

14. 
3.17 
50.2 

9.1 


Per 
cent 

35.6 

12.2 

2.81 
43.4 

6. 


Per 
cent 

45.8 

10.9 

2.9 

35.2 

5.2 


Per 

cent 

28.5 

12.3 
2.94 

47.8 

8.5 


Per 
cent 

23.3 

13.7 
2.67 
55.1 

5.2 


Per 
cent 

42.2 

10.9 

1.65 
41.3 

4. 


Total 


100. 


100. 


100. 


100. 


100. 


100. 


100. 


100. 


100. 


100. 


Minerals 

Phosphorvis 
Calcivmi . . 
Magnesium 
Potassium . 
Sodium • . 
Iron .... 


■ 


Per 
cent 

.803 
1.508 
.051 
.17 
.108 
.028 


Per 
cent 

.677 
1.281 
.037 
.146 
.094 
.017 
.013 


Per 
cent 

.67 
1.177 
.048 
.171 
.109 
.015 
.016 


Per 
cent 

.488 

.944 

.034 

.144 

.09 

.026 

.021 


Per 
cent 

.524 

.965 

.031 

.14 

.077 

.029 

.014 


Per 
cent 

.454 
.846 
.029 
.123 
.072 
.024 
.012 


Per 
cent 

.484 
.886 
.033 
.131 
.096 
.021 
.011 


Per 
cent 

.492 
.915 
.031 
.138 
.076 
.018 
.016 


Per 
cent 

.465 
.771 
.032 
.163 
.082 
.015 
.021 


Per 
cent 
.286 
.455 
.019 
.115 
.054 
009 


Sulfur . . 


.015 


.012 


Live weight, lbs. 
Age 


1,232 

4jTS. 


1,419 
4yrs. 


258.8 
9.5 
wks. 


97.6 
lyr. 


105.1 
yrs. 


127.2 

yrs. 


239.4 
yrs. 


84.4 

Hyr. 


93.9 


185. 







154 THE FEEDING OF ANIMALS 

220. Distribution of mineral elements in animal body. 
— ^The bones carry the greater part of the ash elements. 
Fresh bones are approximately one-quarter ash. The 
muscles have between 1 and 2 per cent of ash, and the 
blood from eight to nine parts in a thousand. The dis- 
tribution of the mineral elements in the animal body is 
somewhat as follows: phosphorus and calcium predom- 
inate in the bones; sodium salts are found largely in the 
blood, the serums, and lymph; potassium salts exist most 
abundantly in the blood, muscles, brain, and liver. Iron 
compounds are found most largely in the blood, lungs, 
liver, and spleen; and magnesium in the lungs, muscles, 
and nervous tissue. Sulfur, as has been seen, is asso- 
ciated with many of the proteins and is found in espec- 
ially large proportions in hair and horn. 

221. Relation of mineral elements to elimination of 
waste products. — In this respect, iron exercises a particu- 
larly important function. As has been seen, it is con- 
tained in the hemoglobin of the red corpuscles. In the 
lungs, oxygen becomes lightly attached to this hemo- 
globin and is carried to the various parts of the body 
where it is used for the oxidation of the organic com- 
pounds in the food. The red corpuscles seize upon the 
carbon dioxid which is one of the products of this oxida- 
tion and carry this to the lungs where it is eliminated. 
As these oxidation processes furnish the energy for sus- 
taining the activities of the animal body, it appears that 
iron is a most important factor in animal metabolism. 

222. Relation of mineral elements to a proper equilib- 
rium between the acids and bases of the animal body. — 
The cleavage processes which take place in the use of 
food compounds give rise to sulphuric and phosphoric 
acids, and these together with certain organic acids must 



FUNCTIONS OF THE NUTRIENTS ' 155 

be neutralized through the presence of certain basic ele- 
ments. Sodium, potassium, and calcium function in 
this relation. If this neutralization did not occur, the 
animal would be seriously affected and in time die. As a 
matter of fact acidosis (acid condition) has not been 
demonstrated with farm animals. The acidity or the 
alkalinity determines the function of the action of certain 
enzyms in the digestion of food, as, for instance, while the 
pepsin of the stomach acts most effectively in an acid 
solution, the trypsin and other enzjTns of the duodenum 
act only in an alkaline medium. 

223. Relation of mineral elements to osmosis. — 
The transference of substances in solution from one part 
of the body to another involves the passage of solutions 
through various membranes and tissues, as, for instance, 
from the alimentary canal into the blood and from the 
blood into various tissues which are nourished through 
such distribution. The penetrability of these membranes 
seems to be dependent upon the presence of mineral salts. 

224. Relation of mineral elements to muscular con- 
trol. — ^The contraction of both the voluntary and invol- 
untary muscles seems to be dependent upon a certain 
balanced chemical environment involving salts of calcium, 
magnesium, sodium, and potassium. 

225. Relation of mineral elements to tissue develop- 
ment. — It has been shown that the eggs of certain marine 
fishes segment normally only in water containing a mix- 
ture of certain salts of a certain concentration, these 
being the salts of the alkalies and alkaline earths. 

226. General considerations. — It is easily seen that 
the mineral salts sustain very complex relations to the 
growth of animal tissue and to the maintenance of animal 
life. It is a matter of common observation that when an 



156 THE FEEDING OF ANIMALS 

animal is given food free from the compoimds of the 
mineral elements, the animal suffers physical deteriora- 
tion and finally dies. In considering the matter of a 
sufficient supply of mineral element, the feeder should 
consult tables showing the ash composition of the various 
feeding-stuffs. 

227. Supply of mineral elements (see Pars. 48-54). — 
The supply of the mineral elements in the food of the 
various classes of animals has not until a comparatively 
recent time received extensive consideration. It has been 
practically held that nature has made a generous provision 
for supplying the animal's needs for mineral substances 
in our home-raised feeding-stuffs and that mixed rations 
as usually fed contain in variety and quantity all that is 
needful of these nutrients for the various kinds of pro- 
duction. It was clearly proved sometime since that an 
extra supply of mineral compounds is needed for laying 
hens, especially calcium compounds for the formation 
of egg shell, and it was also shown that the proper devel- 
opment of the bony structure of swine is not secured 
through feeding cereal products alone, particularly exclu- 
sive corn-feeding, but the mixed rations for bovine pro- 
duction have not been questioned in this direction. 

It has remained for Forbes in a recent extensive and 
exceedingly important investigation as to the mineral 
supply of liberally producing cows to show that during 
full milk production, even when the animals were fed 
on rations that are regarded in practice as highly satis- 
factory, there were important losses of calcium, mag- 
nesium, and phosphorus from the cow*s skeleton. It is 
suggested that the decreasing milk-supply during a 
given period of lactation and the sometimes observed 
failure of a highly producing cow to carry her high pro- 



FUNCTIONS OF THE NUTRIENTS ' 157 

duction successfully through two periods of lactation are 
due to the removal from the body of these mineral elements 
not supplied in sufficient abundance in food. It would 
seem, however, that ordinarily there are periods during 
which a milch cow recovers her loss of mineral elements. 

Forbes calls attention to the importance of iodine in 
animal metabolism. It has long been known that in the 
cases of abnormal physical development accompanied 
by inferior intellectual quality, such subjects being known 
as cretins, the physical and mental conditions have been 
improved by an extract of the thjToid gland which car- 
ries iodine. An extensive investigation of many feeding- 
stuffs shows an absence of iodine in some and only traces 
or very small percentages in others. It would appear, 
however, that under the ordinary system of feeding mixed 
rations the iodine supplied to our domestic animals 
is sufficient. 

228. Relative efficiency of different phosphorus com- 
pounds. — ^The mineral elements of foods may be supplied 
to the animal in various forms. This is particularly true 
of phosphorus which is used so freely by growing animals 
and milch cows. Because of the importance of this ele- 
ment the problem of the relative nutritive efficiency of 
organic as compared with inorganic phosphorus com- 
pounds has been much studied. The organic forms found 
in foods are in part nucleo-proteins, phospho-proteins, 
phytin, and similar compounds found in grains, and 
lecithin and glycero-phosphates. In an admirable resume 
of the whole subject, Forbes shows that the data secured 
on this question give conflicting testimony but that the 
majority of evidence seems to favor the conclusion that 
the organic phosphorus compounds are more efficient, 
for some species at least, than the inorganic, such as cal- 



158 THE FEEDING OF ANIMALS 

cium phosphate. It seems clear, however, that growth 
can be secured where only inorganic phosphorus is fed, 
and in many experiments this form has seemed as efficient 
as the organic. The synthesis in the animal of such com- 
pounds as the nucleo-proteins can hardly be doubted. 
The fact of such synthesis does not show that organic 
phosphorus compounds may not be in general more 
efficient than inorganic. This question has some economic 
importance because it is well to know whether so cheap 
a material as phosphatic rock may be a useful source for 
fortifying the phosphorus supply of a ration. 

FUNCTIONS OF PKOTEIN 

229. Proteins as tissue-formers. — While there are at 
present many unsolved problems relative to the nutri- 
tive offices of protein, there is no reasonable doubt that 
the vegetable proteins are the primary and main source 
of all similar substances in the animal body. From these 
proteins are formed the muscles, the connective tissues, 
the skin, hair, horn, and hoofs, and the major part of 
the tissues of the secretive and excretive organs; in short, 
that they are the source of a large proportion of the 
working parts of the animal body. So far, scientffic 
research has not succeeded in demonstrating that a pro- 
tein is ever synthesized (built up from simple compounds) 
outside of the plant. It appears that bodies of this class 
must in the main come to animal life fully elaborated. 
This is a truth of great significance even in its relation 
to the nutrition of farm animals. The nitrogenous tissues 
are those that largely, determine the vigor and quality 
of any animal, and as these are formed rapidly in the early 
stages of growth, a normal and unrestricted develop- 



FUNCTIONS OF THE NUTRIENTS ' 159 

ment demands an* abundant supply of protein food. It 
is also true of mature animals that sufficient protein is 
not only necessary to health and vigor, but it is essen- 
tial to production that is satisfactory in quantity and 
quality. 

230. Protein as a source of fats. — ^The functions of 
protein are not restricted, however, to the use already 
described, for it is utilized in more ways than any other 
class of nutrients. It was held at one time that outside 
the vegetable fats it is the sole source of animal fats, and 
this view was, not so very long ago, to some extent 
accepted. Indisputable proof to the contrary is now in 
our possession. Certainly we must be convinced that 
nitrogen compounds of the food are, with some species, 
not the most important source of animal fat, for various 
investigators, such as Lawes and Gilbert, Soxhlet, and 
others, have shoTvn upon the basis of searching experi- 
ments that sometimes over four-fifths of the fat stored 
by pigs must have had its origin outside the food protein 
and fat. Jordan showed that milk-fat may be largely 
synthesized from carbohydrates. Besides all this, the 
common experience of feeders that foods highly non- 
nitrogenous are often the most efficient for fattening 
purposes is good evidence that fat formation is not 
greatly dependent upon the protein supply. Neverthe- 
less, the possibility of producing animal fat from protein 
now appears to be demonstrated. 

231. Protein as a source of energy. — ^Protein can 
unquestionably serve as fuel, or, in other words, as a 
source of energy. The amount so used depends much 
upon the animal fed and the character of the ration. In 
the case of a dog eating an exclusive meat diet or of a 
mature fattening animal which receives a ration liberally 



160 THE FEEDING OF ANIMALS 

nitrogenous, the greater part of the protein eaten is not 
stored but, excepting the nitrogen compounds of the 
urine, is used as fuel. With milch cows or young animals 
growing vigorously a much larger proportion escapes 
oxidation. The fuel value of protein will be discussed 
later under another head. 

FUNCTIONS OF CARBOHYDRATES 

232. Carbohydrates the chief source of energy. — 

Carbohydrates are usually characterized as the fuel portion 
of the food, or that part which is oxidized to produce the 
various forms of energy. This conception of the function 
of these bodies is correct in the sense that in the case of 
farm animals they constitute the larger part of the fuel, 
although not the whole of it. 

233. Proportion of ration used as fuel.— For instance, 
in the case of a cow eating daily sixteen pounds of diges- 
tible organic matter, giving thirty pounds of milk con- 
taining 15 per cent of solids, and neither gaining nor 
losing flesh, not far from five pounds of this organic 
matter would be found in the milk and urine, leaving 
about eleven pounds to be used as fuel, about a pound 
and a half of which might be derived from the protein 
and fat, the remainder, or nine and one-half pounds, con- 
sisting of carbohydrates. If a fattening steer were eating 
the same amount of the same kind of food and gaining 
two pounds of live weight daily, the body increase and 
urine would contain not over two and one-half pounds of 
dry matter, leaving not less than thirteen and one-half 
pounds to be oxidized, of which twelve pounds might 
consist of carbohydrates and fat, mostly the former. It 
is clear, then, that while other bodies serve as fuel, the 



FUNCTIONS OF THE NUTRIENTS 161 

carbohydrates furnish much the larger part of that which 
is needed for this purpose. 

234. Fats from carbohydrates. — Contrary to views 
that held for a time, it is now well established that the 
animal fats may have their source in the carbohydrates; 
in other words, starch and sugar and related bodies may 
serve the main purpose in feeding animals for fattening. 
In many experiments, notably those with swine, the pro- 
tein and fat of the food have fallen far short of account- 
ing for the fat in the body increase, sometimes much the 
greater part of the latter having no possible source other 
than the carbohydrates. A practical expression of this 
general conclusion concerning the fat-forming function 
of carbohydrates is seen in the well-recognized value of 
corn meal as a fattening food, a feeding-stuff nearly seven- 
tenths of which consists of starch and its allies. Experi- 
ments with milch cows leave no doubt that milk-fat may 
also be derived from carbohydrates. These more recent 
views tend to magnify the importance of the carbo- 
hydrates as nutrients. 

FUNCTIONS OF THE FATS AND OILS 

235. Fats and carbohydrates similar in function. — 

So far as is at present known, the possible uses of the 
food fats and oils and of the carbohydrates are similar. 
In other words, both may serve as fuel and both may be 
a source of animal fat. The differences are that the supply 
of carbohydrates is much the larger, and the fuel value 
of a unit weight of fats is over twice as great as that 
of starch and sugar. Moreover, it seems possible for a 
food fat to become deposited as such in the animal or 
in milk without essential change, whereas fat formation 

K 



162 THE FEEDING OF ANIMALS 

from carbohydrates involves complex chemical trans- 
formations not fully understood. 

FOOD AS A SOURCE OF ENERGY 

236. Work performed by the animal organism. — 

The living animal, either as a whole or in some of its parts, 
is constantly in motion. This means that the animal 
mechanism is ceaselessly performing work. Even if the 
body is apparently quiet, the heart beats, pumping 
blood to all parts of the body, the lungs are expanded 
and contracted, and the stomach and intestines keep up 
the movements which are essential to digestion. Besides, 
a living body is the seat of continuous, invisible and com- 
plex chemical and physical changes that, if not work in 
the common meaning of the term, are its equivalent. 
Walking, trotting, pulling, lifting, pumping blood, 
breathing, masticating, digesting and assimilating food 
represent, then, a great variety of operations of those 
living machines which we have named horse, ox, cow, 
and sheep. 

237. Work requires the expenditure of energy. — 
Now work requires the expenditure of energy. The 
projection of a rifle ball through space at the rate of 2,000 
feet a second is work. The ball does not move of itself, 
but is propelled by the application of the energy stored in 
a powerful explosive. Back of every one of our great 
mechanical operations, such as pumping, grinding, and 
moving railroad trains, will always be found some sort 
of energy, and what is true of machinery made of wood 
and iron is equally true of that made of bone and muscle. 
The fact that the mechanism is alive does not abrogate 
a single physical law, so that the fundamental principles 



FUNCTIONS OF THE NUTRIENTS 163 

of energy as applied to machines are as fully applicable 
to the activities of animal life. 

238. The animal organism does not originate energy. — 
It is safe to go farther and say that the animal organism 
does' not originate energy. Among the fundamental 
conceptions upon which all our knowledge of chemical 
and physical laws rests is this, that energy and matter 
are indestructible, and, moreover, that the sum total 
of these in the universe is unchangeable. If, then, the 
horse expends the muscular energy necessary to draw a 
load of one ton over 10 miles of road, the equivalent of 
this must have been supplied to his body from some out- 
side source. He could not create it. We know that this 
is so, and we also know it is conveyed to the animal 
in the food. % 

239. The nature of energy. — A definition of energy is 
difficult. It can be illustrated by pointing out some of 
its manifestations. It is a common observation to see a 
blacksmith hammer an iron rod until it is red hot. The 
motion of the hammer-head descending with great veloc- 
ity was suddenly arrested when it came in contact with 
the rod. The hammer-head was driven by energy sup- 
plied from two sources, gravity or the energy of position, 
and energy exerted through the blacksmith's arm, that 
is, energy supplied through oxidation in the blacksmith's 
body. When the hammer met the iron rod on the anvil, 
the mass motion ceased. The operating energy was not 
annihilated, but it appeared in another form. The motion 
of the hammer-head (kinetic energy), a mass of matter, 
was communicated to the molecules of the iron rod, and 
as the vibrations of the molecules increased in rapidity, 
the rod grew hotter and hotter. Here we have another 
manifestation of energy, viz., the motion of the molecule. 



164 THE FEEDING OF ANIMALS 

The iron rod might have been heated in another way — 
by plunging it into burning charcoal. Somehow, when it 
is deposited in the plant, there becomes stored in this 
carbon, in a way about which we can only theorize, what 
we may call chemical energy, which, when combustion 
occurs, is changed into heat or molecular motion. From 
these phenomena we learn that not only are there several 
manifestations of energy, but that one manifestation is 
transferable into another. 

240. Transformations of energy through the use of 
machinery. — Perhaps another illustration may still fur- 
ther serve our purpose. A small dynamo is being run 
by a pair of horses working in a tread-power such as is 
used for threshing grain. The horses are constantly 
climbing up a moving treadway and thereby communi- 
cating motion to machinery. The energy thus applied 
is the result of combustion in the body of the horse. This 
motion, is, by the dynamo, converted into electricity, 
which, by passing through the carbon film of an incandes- 
cent lamp and there meeting resistance, is in part, at 
least, manifested as heat. We have, then, in a chain, 
muscular effort, motion of the mass (pulleys and wheels), 
electricity, and heat, all manifestations of energy and 
all transferable one into the other. 

241. The horse a machine. — ^This is a fairly good pic- 
ture of what goes on with the horse himself, externally 
and internally, in sustaining life and performing labor 
for his owner. It is now known that through the combus- 
tion of the carbon compounds of vegetable and animal 
origin, which serve as nutrients, chemical energy may be 
transformed into those other forms that are manifested in 
the activities of living beings, and it is a notable triumph 
of science to be able to declare with certainty that the 



FUNCTIONS OF THE NUTRIENTS ' 165 

ceaseless and multiple activities of life on this planet are 
sustained by an energy which comes to the plant in the 
sun's rays and is stored there through the synthesis of 
carbon compounds. 

242. Measurement of energy. — It is obvious that if 
the internal and external work performed by the animal 
is sustained by the food, it is desirable to measure the 
energy available in different feeding-stuffs, provided, 
of course, that they differ in this respect. In order to 
measure anything, we must have a standard or unit of 
measurement. In this case it cannot be a unit of space 
or of mass, that is, we cannot declare that corn meal con- 
tains so many cubic feet or pounds of available energy. 
Energy has neither dimensions nor weight. If we meas- 
ure it at all, it must be by units of temperature or of work 
performed. Units of this latter kind are the ones applied 
to the measurement of food energy. The one that has 
been most commonly used is the Calorie, this being the 
energy w^hich in terms of heat is sufficient to raise the 
temperature of one pound of water 4° F. Expressed in 
terms of work, the Calorie (large) is very nearly 1.53 
foot-tons, or in other words, it is equivalent to the w^ork 
involved in lifting one ton 1.53 feet. Heat units are 
expressed in both the large Calorie and the small calorie. 
When the former is indicated, the word begms with a 
capital letter. The Calorie represents 1,000 calories. 
Armsby proposes the use of the term ilierm^ which repre- 
sents 1,000 Calories, which renders less cumbersome the 
figures given for the energy of a ration. 

243. Detennination of energy units in feeding-stuffs. — 
The total energy or heat units developed in the combus- 
tion of feeding-stuifs is determined in an apparatus 
called a calorimeter. The latest form of this device is one 



166 



THE FEEDING OF ANIMALS 



in which the ground hay is burned under pressure in the 
presence of pure oxygen, and the heat evolved is all 
used in warming a known weight of water. Data are thus 
obtained from which it is possible to calculate the Calories 
in the particular material burned. The energy value of 
single compounds, such as albumin, starch, and sugar, 
may also be found in the same way, as has been done in 
a large number of instances. These data show that the 
heat resulting from the combustion of the compounds of 
a given class is not the same in all cases. The value in 
large Calories of one gram of several pure nutrients is 
shown in the following table : 



Wheat gluten . 
Gliadin . . . . 
Glutenin . . . 
Plant fibrin 
Serum albumin 
Milk casein 
Yolk of egg 



Carbohydkates 



Starch . . 
Cellulose . 
Glucose 
Cane-sugar 
Milk-sugar 
Maltose . 
Zylose . . 



Table XXVIII 




Proteins 




Calories 




Calories 


5.99 


Egg albumin . . . 


5.73 


5.92 


Muscle (pure) . . . 


5.72 


5.88 


Blood fibrin . . . 


5.64 


5.94 


Peptone 


5.30 


5.92 


Wool 


5.51 


5.86 


Gelatin 


5.27 


5.84 


Asparagin (amide) 
Fats 


3.45 


Calories 




Calories 


4.18 


Of swine 


9.38 


4.18 


Of oxen 


9.38 


3.74 


Of sheep 


9.41 


3.95 


Maize oil .... 


9.28 


3.95 


Olive oil 


9.47 


3.95 


Ether-extract of oats 


8.93 


3.74 


Ether-extract of barle; 


y 9.07 



The heat values of a gram of the dry substance of 
various cattle foods, which is a mixture of the several 
nutrients, were found by recent determinations to be the 
following, expressed in calories: 



FUNCTIONS OF THE NUTRIENTS ' 167 

Table XXIX 

Calories Calories 

Mixed hay 4.39 Com meal 4.47 

Alfalfa hay 4.40 Linseed meal .... 5.04 

Oat straw 4.48 Flaxseed meal .... 6.93 

Sugar-beets .... 3.93 Rice meal 4.40 

These figures mean that when a gram of each of 
these materials is wholly bm-ned the heat produced 
is as stated. 

244. Metabolizable energy. — ^We must distinguish, 
however, between the heat produced when any food 
substance is wholly oxidized in a calorimeter and the heat 
or energy which is available (metabolizable) when the 
same material is applied to physiological uses. It never 
happens that the combustible portion of a ration is 
entirely oxidized in the animal. 

245. Loss of food energy in feces. — In the first place, 
the food of domestic animals is practically never all 
digested and, as only the digested portion furnishes 
energy, the available fuel value of a ration must be based 
primarily, not on the total quantity of dry matter it 
represents, but on the amount which is dissolved and 
passes into the blood. If all feeding-stuffs or rations 
were digested in the same proportion and with the same 
ease, their total fuel values might show their relative 
energy worth, but as digestion coefiicients for dry matter 
vary from less than 50 per cent with the straws to nearly 
90 per cent with some of the cereal products, it is evident 
that the fuel waste in the feces is not uniform. 

246. Loss of food energy in urine. — In the second 
place, the digested proteins are never fully burned. A 
portion of these compounds always passes off in the urine 
unoxidized, the fuel value of which is lost to the animal. 



168 THE FEEDING OF ANIMALS 

For this reason the available energy of the digested pro- 
teins is about one-fourth less than the total. 

247. Loss of food energy in gases. — In the third place, 
there is, with ruminants and horses at least, an escape 
from the alimentary canal of unconsumed gases, due to 
the fermentations which take place during digestion. 
These gases, mostly methane (marsh gas) with some 
carbon dioxid and from green leguminous plants some 
hydrogen sulfide and nitrogen, have their source in the 
carbohydrates and crude fiber, and Kellner found them 
to represent from 10 to 20 per cent of the total energy 
value of the dry substance digested from various materials. 
From twenty experiments, upon five different animals, 
Ktihn found the loss in methane to be over one-seventh 
the energy of the digested crude fiber and nitrogen-free 
extract. 

248. Recent determinations of metabolizable energy. 
— ^The most accurate and extensive determinations of 
metabolizable energy that have been made in this coun- 
try, or perhaps anywhere, are the result of recent inves- 
tigations by Armsby and Fries with the aid of a respira- 
tion calorimeter. These involved analysis of the feeds 
used and determinations of the total energy of the feeds 
and of the losses through the various avenues indicated 
above. In carrying on this work, nine steers were used, 
involving 3,401 experiments. Without giving any atten- 
tion to the technics of the work, which required a costly 
and extensive equipment of men and apparatus and 
involved thousands of accurate chemical analyses of 
foods and the different forms of excreta, the following may 
be cited as an example of the necessary computation of 
losses of chemical eneigy from a ration through the 
excreta and the methane: 



FUNCTIONS OF THE NUTRIENTS 



169 



Table XXX 

Period 2 Period 3 

Calories Calories 

Total energy of feed — 

Timothy hay 12,477 12,618 

Grain mixture, No. 1 12,549 . . 



Total 25,026 12,618 

Energy of excreta — 

Feces 7,371 5,247 

Urine 1,536 627 

Methane 2,098 1,057 



Total 11,005 6,931 



MetaboHzable energy 14,021 5,687 

The above computation is for a mixed ration contain- 
ing both coarse fodder and grain. In order to ascertain 
the losses from the grain itself, those for the hay having 
been determined by other experiments, the following 
computation was necessary: 



Table XXXI 





Chemical 
energy 
of feed 


Chemical energy of excreta 


Metabo- 




Feces 


Urine 


Methane 


Hzable 
energy 


Total ration 

Computed for hay . . 


Calories 

25,026 

12,477 


Calories 

7,371 
5,254 


Calories 

1,536 
591 


Calories 

2,098 
1,003 


Calories 

14,021 
5,629 


Grain mixture by dif- 
ference 


12,549 


2,117 


945 


1,095 


8,392 



249. Distribution of losses of food energy. — In the 
next table there are given for eight individual feeding- 
stuffs and several mixed rations and grain mixtures the 
percentage of losses through the different avenues and 



170 



THE FEEDING OF ANIMALS 



the percentage of metabolizable energy, or in other words, 
that which may be appUed to use by the animal, from the 
several materials involved in the experiments: 



Table XXXII. 



Feeding-stuff 



Timothy hay 

Red clover hay 

Mixed hay 

Alfalfa hay 

AlfaKa meal 

Maize stover 

Maize meal 

Wheat bran 

Grain mixture, No. 1 

Grain mixtm-e, No. 2 

Hominy chop 

Alfalfa hay and grain mixture, No. 2 
Mixed hay and maize meal .... 
Mixed hay and hominy chop . . . 



Percentage losses 



In 

feces 



48.13 
40.95 
43.92 
47.54 
42.01 
42.82 
14.74 
31.77 
17.91 
22.03 
12.15 
30.27 
24.22 
28.02 



In 
urine 



3.57 

6.82 
5.17 
5.58 
5.89 
4.24 
3.32 
5.38 
7.20 
4.54 
3.84 
4.83 
3.87 
4.44 



In 
CHi 



6.94 
5.95 
7.35 
5.94 
6.11 
7.88 
9.75 
7.44 
7.84 
9.06 
9.20 
7.98 
8.89 
8.15 



Percentage 
metabol- 
izable 
energy 



41.36 
46.28 
43.56 
40.94 
45.99 
45.06 
72.19 
55.41 
67.05 
64.37 
74.81 
56.92 
63.02 
59.39 



It will be noted that the main loss is by way of the 
undigested food residue. The energy loss in the urine 
ranged from 3.3 to 7.2 per cent. The loss from methane 
ranged from 5.9 to 9.7 per cent of the total dry matter, 
or from 4.2 to 5.1 grams to 100 grams of digestible car- 
bohydrates, the average being 4.8 grams. Kellner found 
4.2 grams, and these figures may be taken as a basis for 
the estimate of the probable loss of chemical energy 
through fermentations. The undigested residue varies 
greatly according to the nature of the food. These authors 
have investigated the influence of the quantity of the 
ration upon the losses of chemical energy. 



FUNCTIONS OF THE NUTRIENTS ' 171 

250. Influence of size of ration on losses of methane. — 

The losses through gas evolution were found to be greater 
in twenty-nine cases out of thirty-one with the lighter 
ration and tended to be somewhat greater on the mixed 
ration with a very much larger proportion of readily 
soluble carbohydrates. This simply means that the 
"bacterial fermentation of the carbohydrates in the di- 
gestive tract of cattle proceeds to a distinctly greater 
extent on light than on heavy rations." 

251. Influence of size of ration on losses in the im- 
digested residue. — As is well known, this loss will be by 
no means uniform as this residue is proportionately much 
larger with coarse foods than with grain foods. In these 
comparisons there seemed to be practically no difference in 
the proportion of loss as between heavy and light rations, 
these results not agreeing with former observations. 

252. Influence of individuality on energy losses. — 
Comparison was made between a pure-bred Shorthorn 
steer and a so-called scrub. Practically no difference in 
the loss of chemical energy was discovered as between 
these two animals. 

253. Estimates of metabolizable energy on the basis 
of digestible organic matter. — It is discovered that the 
metabolizable energy in a unit of digestible organic 
matter is fairly uniform as between the different coarse 
fodders on the one hand and the various concentrates 
on the other. Various investigators have studied this 
question and their results show a satisfactory agreement. 
It appears that the metabolizable energy which may be 
derived from the several feeding-stuffs will vary quite 
directly with the proportion of digestible dry matter. 
The following table shows the figures reached by several 
investigators : 



172 THE FEEDING OF ANIMALS 

Table XXXIII. 

Coarse Feeds 

Armsby and Fries: per kilo 

Timothy hay 3.49 

Red clover hay 3.49 

Mixed hay 3.39 

Alfalfa hay and meal 3.61 

Maize stover 3.45 

Average 3.48 

Kellner and Kohler: 

Meadow hay 3.50 

Oat straw 3.74 

Wheat straw 3.31 

Extracted straw 3.64 

Average 3.55 

Concentrates 
ArmGby and Fries: 

Maize meal 3.80 

Wheat bran 3.99 

Grain mixtm*e, No. 2 3.88 

Average 3.89 

Grain mixture, No. 1 = 3.91 

Hominy chop 4.08 

Average 4.00 

Kellner and Kohler: 

Beet molasses 3.47 

Starch 3.60 

Wheat gluten 4.79 

It is self-evident, of course, that the metabolizable 
energy will be greatly influenced by the percentage of fat 
or oil in a ration, as the fats have more than double the 
energy value of the carbohydrates. 



FUNCTIONS OF THE NUTRIENTS 



173 



254. Comparison of metabolizable energy in coarse 
fodders and grains. — ^The following table selected from 
the data of the same authors admits of a direct com- 
parison of the proportions of metabolizable energy in 
coarse fodders and grains. 

Table XXXIV 

Coarse Foods 



Timothy hay 

Red clover hay . . . 

Mixed hay 

Alfalfa hay and meal 
Maize stover . . . . 

Average 



Gross 

energy per 

kilo dry 

matter 



Therms 

4.51 
4.46 
4.39 
4.37 
4.33 



4.41 



Losses 

energy per 

kilo dry 

matter 



Metabolizable energy 



Per kilo 
dry 

matter 



Therms 

2.66 
2.46 
2.48 
2.45 
2.38 



Therms 

1.85 
2.00 
1.91 
1.91 
1.95 



2.49 



1.92 



Per kilo 

digestible 

organic 

matter 



Therms 

3.49 
3.49 
3.39 
3.60 
3.45 



3.48 



These data show that approximately 56 per cent of the 
gross energy of the dry matter fed in coarse fodders is 
lost in the feces, urine, and gases evolved. 



Grains 





Gross 

energy per 

kilo dry 

matter 


Losses 

energy per 

kilo dry 

matter 


MetaboHzable energy 




Per kilo 

dry 
matter 


Per kilo 

digestible 

organic 

matter 


Maize mea] 

Wheat bran 

Hominy chdp 


Therms 

4.44 
4.53 

4.71 


Therms 
1.11 

2.02 
1.19 


Therms 

3.33 
2.51 
3.52 


Therms 

3.80 
3.95 
4.07 


Average 


4.56 


1.44 


3.12 


3.94 



174 THE FEEDING OF ANIMALS 

The loss from the grains is relatively much less than 
from the coarse fodders, being only an average of 31.5 
per cent. This is easily accounted for by the greater 
digestibility of the grains. 

We are to understand, then, that the metabolizable 
energy of a ration is represented by the fuel value of the 
dry matter which is digested from it, minus the dry mat- 
ter of the urine and that lost in gases. 

If, however, we wish to know the actual energy gain 
to the animal from a particular ration, we must go farther 
than a determination of its available energy. 

255. Net energy. — Within a comparatively short time 
we have begun to speak of the net energy of foods, and as 
this is a practical consideration which is likely to be the 
subject of much future discussion, it is well to notice it 
in an explanatory way. As we have learned, food is not 
applied to use until it reaches the blood. Between the 
time when it is taken into the mouth and when it passes 
into the circulation, it must have work expended on it 
in the way of mastication, solution, moving it along the 
digestive tract and assimilation, and it seems probable 
that the amount of this work for a pound of food must 
vary greatly in different cases. In fact, this seemed to be 
proven by the result of some masterly investigations con- 
ducted by Zuntz and associates in Germany. 

256. Work of mastication (Zuntz). — Zuntz determined 
the oxygen consumption, that is, increased energy used, 
during the mastication of several feeds by a horse as 
compared with what occurred with the animal at rest. 
In considering the data shown in Table XXXV it should 
be remembered that mastication is only one factor of the 
loss of energy involved in the appropriation of food, and 
perhaps a minor one. 



FUNCTIONS OF THE NUTRIENTS 



175 



Table XXXV 



Feed 


Niimber 

of 
experi- 
ments 


Additional 
oxygen 
con- 
sumed 


Additional 

CO2 
excreted 


Equivalent 
energy 


Oats and cut straw (6:1) 

Hay 

Hay, oats, and cut straw 
Maize and cut straw (6:1) . 

Green alfalfa 

Computed for oats alone 
Computed for maize alone . 


8 
8 
8 
2 

7 


Liters 

12.964 

33.840 

20.072 

7.133 

6.171 


Liters 

10.679 

27.813 

17.677 

6.205 

4.980 


Calories 

64.17 
167.44 
100.79 
35.72 
30.42 
47.00 
13.80 



257. Difference in total energy use with different 
rations. — Zuntz and Hagemann determined the oxygen 
use and carbon dioxid excretion during an exclusive hay 
diet as compared with a diet of mixed hay and grain. 

Table XXXVI 





Hay 


Hay 
and grain 


Time since last fed hours 


2.6 


2.8 


Ration — 






Hay kilos 


About 10.5 


4.75 


Oats kilos 




6. 


Straw kilos 




1. 


Total digested nutrients (fat x 2.4) grams 


4,125 


5,697 


Per kilogram and minute — 






Oxygen consumed .... cub. cent. 


3.9837 


3.6986 


Carbon dioxid given off . . cub. cent. 


3.6586 


3.6695 


Energy set free (computed) . gr. Cals. 


19.552 


18.339 


Energy katabolism per day and head 






Calories 


12,450 


11,678 



The comparison of the energy use for the consump- 
tion of the exclusive hay ration and hay-and-grain ration 
shows that the latter, carrying 5,697 grams of digesti- 



176 THE FEEDING OF ANIMALS 

ble matter, used 1,213 gram-calories less energy than the 
exclusive hay ration, carrying 4,125 grams of digestible 
matter. The hay ration cost for consumption 4.7 Calories 
per gram of digestible dry matter and the mixed ration 
only 3.2 Calories. This increased use of energy can only 
be explained by assuming that the cost of consuming the 
grain was proportionately less than that of the hay, a 
difference presumably due to the greater cost of masti- 
cating the hay. 

The differences revealed by Kuntz's figures are inter- 
esting and important. Chewing green food cost in labor 
only about 18 per cent of the effort required to masti- 
cate its equivalent of dry hay, the proportions of labor 
for hay, oats, and corn being in the ratio of 100, 28 
and 8J^. 

This author goes farther and calculates that the 
work of mastication and digestion combined is 48 per 
cent of the energy value of the digested material from hay 
and 19.7 per cent of that from oats. He also makes the 
statement that in general the coarse foods have 20 per 
cent less net energy value than the grains. All these 
deductions are based upon the excess of oxygen used by 
the animal when engaged in the work of chewing and 
digestion, over that used when at rest. It would follow 
from these results that anything in the way of growth or 
treatment of a fodder which tends to toughen or harden 
the tissue reduces the net energy value. 

258. The work of digestion. — Armsby regards the 
work of digestion outside of mastication as a small factor. 
His experiments when he attempted to measure the work 
of mastication by the increased heat elimination, showed 
no distinct evidence of such increase. He concludes that 
there must have been an increased production of heat 



FUNCTIONS OF THE NUTRIENTS 



177 



during mastication which was not given off promptly. 
The Zuntz method of measm"ing the increase of oxygen 
consmnption would seem to be the more reliable. 

The results of Kellner and of Armsby and Fries, which 
follow, do not appear to ratify the conclusions of Zuntz 
and Hagemann, although the work of mastication was not 
determined as a separate factor. 

259. Total energy expended in feed consumption. — 
Extensive determinations of the total energy expended 
in feed consumption have been made, both by Kellner 
and by Armsby and Fries. The use of energy in this direc- 
tion is determined by comparing the heat production of 
two rations of unlike quantity, heat production being 
equivalent to the energy expenditure by the animal. 
The increased heat production for the larger ration should 
be credited, therefore, to the increase of material in the 
ration, whether a single feed or a mixture of feeds. 
Results by Armsby and Fries follow: 

Table XXXVII 





Quantity 
of dry 
matter 
eaten 


Total 
heat 
produc- 
tion 


Distribution of heat production 




Stand- 
ing 


Rising 

and 

lying 

down 


Fer- 
menta- 
tion 


Re- 
main- 
der 


Period 4 

Periods 


Grams 

4,892 
2,974 


Cals. 

9,523 
7,791 


Cals. 

1,438 
1,107 


Cals. 

59 
40 


Cals. 
794 

498 


Cals. 
7,232 

6,146 


Difference .... 
Difference per kilo- 
gram of dry matter 


1,918 


1,732 
903 


331 
173 


19 
9 


296 
154 


1,086 
567 



The "remainder," after deducting from the total 
heat production that caused by standing, rising, lying 

Note. — ^In a recent publication by Armsby (Pennsylvania State 
College Bulletin No. 142) the position is emphatically taken that the 
consumption cost with concentrates is as great as with coarse feeds, and 
suggests other factors which obscure differences caused by unlike 
mechanical work. 



178 



THE FEEDING OF ANIMALS 



down, and fermentation, is that which should be charged 
to the work of consumption. As the smaller ration was 
less than the other by 1,918 grams and the heat produc- 
tion was 1,086 Calories less for the smaller ration, it 
appears that the work of consumption was 567 Calories 
to a kilo of dry matter or 258 Calories to a pound. 

260. Calculation of net energy value. — ^The following is 
an example of the calculation of net energy value : 



Table XXXVIII 

Calories 

Total chemical energy 

Losses of chemical energy .... 

In feces 2,062 

In urine 243 

In methane 266 



Calories 



Calories 

4,408 



Total 

Increased heat production 

Total losses .... 



2,571 
1,202 



3,773 



635 
In this way the 



Net energy value 

261. Net energy of various feeds. 

following table was derived from the data secured by 

Armsby and Fries: 

Table XXXIX 



Feeding-stuff 


Gross 
energy 


Losses of 

chemical 

energy 


Energy 
expended 

in feed 
consump- 
tion 


Net 
energy 
values 


Timothy hay 

Red clover hay .... 

*AlfaKahay 

Maize stover 

Maize meal 

Wheat bran 

Grain mixture, No. 1 . . 
Hominy chop ... 


Per kilo 
Calories 

4,518 
4,462 
4,372 
4,332 
4,442 
4,532 
4,685 
4,709 


Per kilo 
Calories 

2,664 
2,461 
2,451 
2,380 
1,115 
2,021 
1,621 
1,187 


Per kilo 
Calories 

782 
962 
1,169 
1,065 
1,434 
1,177 
1,327 
1,365 


Per kilo 
Calories 

1,072 

1.039 

752 

887 
1,893 
1,334 
1,737 
2,157 



*lncludes alfalfa meal. 



FUNCTIONS OF THE NUTRIENTS 



179 



The values arrived at by Kellner are in the next table. 
These differ, as would be expected, somewhat from the 
values reached by Armsby and Fries because of a dif- 
ference in the character of the materials fed. 



Table XL 



Feeding-stuff 



Meadow hay . 
Oat straw . . 
Wheat straw . . 
Extracted straw 
"Grass hay" . 
Rowen . . . 
Barley straw . 
Clover hay . . 
Starch .... 
Peanut oil . . 
Wheat gluten 
Beet molasses 







Energy 


Gross 


Losses of 


expended 


chemical 


in feed 


energ>' 


energy 


consump- 
tion 


Per kilo 


Per kilo 


Per kilo 


Calories 


Calories 


Calories 


4,433 


2,260 


1,254 


4,436 


2,848 


1,014 


4,444 


3,062 


1,138 


4,147 


1,013 


1,160 

1,045 

958 

877 
932 


4,152 


1,101 


1,248 


9,457 


4,165 


1,727 


5,579 


1,974 


2,096 


3,743 


945 


988 



Net 
energy 
values 



Per kilo 
Calories 

919 

574 

244 

1,974 

803 

747 

747 

811 

1,803 

3,565 

1,509 

1,810 



262. Computing net energy values of feeding-stuffs. — 
It is very evident that it is not possible to make direct 
determinations of the net energy values of all feeding- 
stuffs, but these may be estimated with reasonable 
accuracy. The following method of computing these 
estimates may be followed, which is based on the total 
digestible material, and the conclusion that each gram 
of digestible organic matter contains 3.5 calories of 
metabolizable energy. The energy used for feed con- 
sumption is reduced to the percentage of dry matter in 
the three feeds entering into the computation shown in 
Table XLI. 



180 



THE FEEDING OF ANIMALS 
Table XLI 



Total dry matter 

Digestible — 

Protein . . . . 
Carbohydrates 
Fats 

Total digestible 



Alfalfa 
hay 



Per cent 

91.6 

10.58 

37.33 

1.38 



49.29 



Oat 
straw 



Per cent 

90.8 

1.2 
38.64 
.76 



40.6 



Wheat 
bran 



Per cent 

88.5 

12.01 
41.23 

2.87 



56.11 



Alfalfa hay, 1,169 calories X 91.6 per cent dry matter=l,071 

calories per kilogram air-dry feed. 
Oat straw, 1,014 calories X 90.8 per cent dry matter=921 calories 

per kilogram air-dry feed. 
Wheat bran, 1,138 calories X 88.5 per cent dry matter=l,007 

calories per kilogram air-dry feed. 

Alfalfa hay (3.5 calories X 492.9 grams digestible matter) — 1,071 

calories =654 calories per kilogram =29.7 therms per 100 

pounds air-dry feed. 
Oat straw (3.5 calories X 406 grams digestible matter) — 921 

calories =500 calories per kilogram =22.7 therms per 100 

pomids air-dry feed. 
Wheat bran (3.9 calories X 561.1 grams digestible matter) — 1,007 

calories =1,181 calories per kilogram =53.6 therms per 100 

pounds air-dry feed. 

These methods of ascertaining net values of feeds may 
be regarded as complex, but they are unquestionably 
the most accurate of any methods so far developed. 

The results of Armsby and Fries and Kellner do not 
accord with a somewhat widespread teaching that the 
energy expended in the consumption of coarse feeds is 
greatly more for a unit of dry matter than is the case w ith 
the concentrates. It is conceded, of course, that the 
energy expended in the mechanical work of mastication 
must be greater in the coarse foods than in the grain 



FUNCTIONS OF THE NUTRIENTS 181 

feeds. It seems, from the later determinations, however, 
that when all factors are considered, the difference in the 
total energy expenditure in the two classes of feeds is not 
greatly unlike. 

263. Estimation of production values proposed by 
Armsby. — Instead of using net or production values as 
experimentally determined for each individual feed, 
Armsby has computed a table based largely on the 
results of investigations by Kellner. 

This investigator arrived at what is termed the pro- 
duction values of pure nutrients, such as a single pro- 
tein, starch, or one of the fats. His figures are as follows: 



Table XLII. Production Values per Pound 

Calories 

Digestible proteins : . . 1016 

Digestible starch or crude fiber 1071 

Digestible cane-sugar 812 

Digestible fat — 

In coarse fodders and roots 2041 

In grains and by-products 2273 

In feeds with over 5 per cent fat 2585 



In making up the tables of production values, these 
values for pure nutrients are used in connection with a 
given allowance for the expenditure of energy in mastica- 
tion due to the presence of crude fiber. Kellner found it 
was possible to estimate fairly accurately the production 
value of concentrated feeds by means of these factors, but 
in the case of the coarse fodders carrying a much higher 
proportion of fiber such a method of computation was 
not reliable. He found, however, that if he deducted 
from the figures obtained through the use of the produc- 
tion values for pure nutrients 617 calories for each pound 
of crude fiber in the coarse fodder the computed value 



182 



THE FEEDING OF ANIMALS 



was little different from the real value. In the use of 
this method only the true proteins are brought into the 
calculation, so that the values are based upon the digest- 
ible true proteins and the total heat value of the nutrients 
minus the energy expended on the crude fiber. The fol- 
lowing table illustrates production values that have been 
made up after this method, with the exception that the 
deductions for crude fiber are less for the green fodders 
and roots than with the dry coarse fodders.* 



Table XLIII 



Feeding-stviff 



Green fodder and silage — 

Alfalfa 

Corn silage 

Hay and dry coarse fodders- 
Clover hay, red .... 
Corn stover 

Straws — 

Oat straw 

Roots and tubers — 

Rutabagas 

Grains — 

Corn 

Oats 



By-products — 

Brewers' grains, dried 
Cottonseed meal .... 
Gluten feed, dry .... 
Linseed meal, new process 
Wheat bran 



Total 

dry 

matter 



Pounds 

28.2 
25.6 

84.7 
59.5 

90.8 

11.4 

89.1 
89. 

92. 
91.8 
91.9 
90.1 

88.1 



Digest- 
ible 
protein 



Pounds 

2.5 
1.21 

5.41 

1.8 

1.09 

.88 

6.79 
8.36 

19.04 
35.15 
19.95 
29.26 
10.21 



Energy 
value 



Therms 

per 
100 lbs. 

12.45 
16.56 



34.74 
26.53 

21.21 



88.84 
66.27 

60.01 

84.2 
79.32 

74.67 

48.23 



* Since writing the above, Armsby has published a newly computed 
and very full table of production values, based upon the composition of 
feeding-stuffs as found in "Feeds and Feeding," by Henry and Morrison. 
This table, computed by a simpler method than the above, may be found 
in the Appendix. 



FUNCTIONS OF THE NUTRIENTS ' 183 

ENERGY RELATIONS. HEAT REGULATION 

As has been pointed out, the animal body is the field 
of numerous mechanical activities. What is the rela- 
tion of the several nutrients to these manifestations of 
vital energy is an interesting and in some ways an in- 
tensely practical matter. 

264. Relation of protein to muscular activity. — ^The 
belief prevailed at one time that muscular contraction 
caused a wasting of the muscle substance which must be 
replaced by the protein compounds of the food; in other 
words, protein alone was believed to sustain the work of 
the animal body, both internal and external. It would 
follow from this that the more work is done the more 
protein is needed. This view is no longer held. The more 
exact methods of modern research have revealed the 
fact that an increase of muscular effort, even up to a 
severe point, increases but little, if any, the nitrogen 
compounds of the urine, these being the measure of the 
protein that is destroyed. 

265. Energy chiefly from carbohydrates and fats. — 
There has come to light a corresponding fact that the 
consumption of fuel in the body other than proteins 
increases proportionately with the increase of work. 
This means that as animals are ordinarily fed mechanical 
work is largely sustained through the combustion of 
carbohydrates and fats, although a fairly generous 
amount of protein seems to promote the well-being of 
a draft animal. 

266. Heat regulation. — ^As no energy is ever lost, 
into what is the energy converted that is applied to 
muscular contraction.^ It is concluded that muscular 
energy used by the animal is partly transformed into 



184 THE FEEDING OF ANIMALS 

external motion (work) and partly into heat, and this 
certainly is consistent with facts as observed. Violent 
exercise by the animal greatly increases the production 
of heat. We know this is so because under these con- 
ditions an increased amount of blood is thrown to the 
surface of the body, thereby greatly increasing the loss 
of heat by radiation; perspiration sets in and with it the 
consequent evaporation of much more moisture, thus 
disposing of much heat. The dog, and sometimes other 
animals, pants and thereby causes a large loss of heat 
from the expanded surface of the moist tongue. All this 
occurs without reducing the body temperature below 
the normal. In fact, nature adopts these various devices, 
such as increased circulation of the blood and perspira- 
tion, in order to regulate the body temperature and pre- 
vent its rising above the proper point. The explanation 
of this greater heat during labor is that the mechanical 
energy manifested by the muscles is converted to heat, 
which under circumstances of severe exercise is more 
than enough to keep the body at its usual temperatiu-e 
and maintain the usual radiation. When it is severely 
cold, on the other hand, vigorous exercise is sometimes 
necessary in order to keep sufficiently warm. 

267. Animal heat a secondary or waste product. — • 
The view now obtains that under certain conditions 
body heat is wholly a secondary product, that combustion 
first supports muscular activity with heat as a by-prod- 
uct; in fact, that at usual temperatures no food is 
burned primarily to keep the animal warm. Under cer- 
tain conditions there may be combustion of food for the 
specific purpose of warming the body. In any case, 
animal heat is sustained either directly or indirectly by 
the oxidation of the nutrients. 



FUNCTIONS OF THE NUTRIENTS 185 

268. The critical temperature. — Recent investigations 
show that under given conditions there is an air tem- 
perature, called the * 'critical temperature,** at which meta- 
bolism (oxidation) reaches a minimum. If the air tem- 
perature falls below this point thus causing a greater 
radiation of heat from the body surface, increased oxida- 
tion occurs. If the temperature of the air rises above this 
point there is no diminution of oxidation but rather a 
slight increase, hence the conclusion that there is a mini- 
mum oxidation necessary to the maintenance of the vital 
functions which must go on however much the demands 
for the radiation of heat may be lessened by a rise of the 
air temperature. It is evident then that at the higher 
air temperatures there is an excess of oxidation above 
that which is required for warming the animal, so that 
some heat must be thrown off as a waste product. Which- 
ever way the air temperature moves from the critical point 
there is heat regulation, this being chemical for the lower 
temperatures and physical for the higher. 

The critical temperatures for our various farm animals 
have not been determined, so that we are not yet able to 
draw therefrom conclusions as to the influence of given 
temperatures upon production. The opinion is ventured, 
however, that with animals protected by a coat of hair, 
that are kept under comfortable winter conditions, the 
temperature of the surrounding air does not fall below 
the critical point. 

THE NUTRITIVE INTER-RELATION OF THE FOOD COMPOUNDS 
AND THE NEED OF COMBINING THESE IN THE RATION 

As we have seen, the conclusion reached by many 
extended and severe investigations is that the compounds 



186 THE FEEDING OF ANIMALS 

of foods have certain functions in common. For instance, 
the proteins, carbohydrates, and fats are all oxidized 
wholly or in part to supply the necessary energy for 
muscular activity. The proteins then serve both construc- 
tive and fuel purposes. Carbohydrates and fats are 
alike in being sources of energy through oxidation, and 
in being utilized for the deposition of animal fat. In 
view of these facts, the question arises whether the physi- 
cal welfare of the animal requires the mixture of nutrients 
that commonly exist in the average ration and that is 
enforced in the standards that are recommended by 
students of animal nutrition. It is certain that some 
species of animals may exist wholly on a flesh diet which 
is practically devoid of carbohydrates, but this is not 
true of farm animals. 

269. Protein physiologically necessary. — ^The neces- 
sity of protein in the ration is abundantly demonstrated. 
Many investigations have showTi that when the food 
contains no protein, the waste of body nitrogen continues, 
no matter how abundant is the supply of carbohydrates 
and fats. In other words, a continuous protein cleavage 
is demanded by the animal organism, and no other 
nutrients can serve as a substitute for protein in meet- 
ing this demand. If the food contains no protein, 
body tissue will be depleted. It cannot be said that 
either carbohydrates or fats are an essential part of the 
diet in the sense protein is, because it is possible to sub- 
stitute the one for the other as energy-producers and pro- 
tein for both. 

270. Carbohydrates physiologically economical. — In 
spite of these facts, it is safe to assert that the welfare of 
the animal organism demands a food carrying a mixture 
of the three classes of nutrients. The larger part of the 



FUNCTIONS OF THE NUTRIENTS ' 187 

animal's food is used for the production of energy, and it 
is physiologically economical that this energy be largely 
supplied by the non-nitrogenous nutrients, particularly 
carbohydrates. If the proteins are broken down to 
supply energy, there is always a definite proportion of 
urea and uric acid residue that must be eliminated through 
the kidneys. An unnecessarily heavy protein diet bur- 
dens these organs and floods the system with these nitrog- 
enous wastes. On the other hand, the carbohydrates, 
when not, stored as fat, are completely oxidized to the 
simplest compounds, carbon dioxid and water, which are 
eliminated through the lungs and skin, part of the water 
so formed acting as a solvent of the urinary compounds. 
Investigation seems to prove conclusively that the 
animal body has a physiological preference for carbo- 
hydrates over the fats or other nutrients as a source of 
energy. After the free ingestion of sugar, the respiratory 
quotient in certain experiments has become 1.00 when 
just previously it was much less than 1.00. This demon- 
strates that while fat was being oxidized before the sugar 
was taken, the oxidation immediately changed wholly to 
the sugar. This indicates the physiological adaptability 
of starches and sugars for maintaining muscular activity. 
271. Protein-sparer s.— The carbohydrates and fats 
are sometimes classed as "protein-sparers." This means 
that, with an adequate supply of these bodies in the food, 
protein destruction may be reduced to the lowest pos- 
sible limit. To illustrate, if a man doing moderate work 
were maintaining an energy balance when eating of 
digestible nutrients 218 grams of protein, 400 grams of 
carbohydrates, and 56 grams of fat, and 100 grams of 
digestible carbohydrates were added to the daily food, 
approximately 100 grams of digestible protein could 



188 THE FEEDING OF ANIMALS 

undoubtedly be withdrawn from the daily food without 
causing any drain upon body protein to meet the demands 
of the organism. As stated, however, such a substitution 
cannot be carried beyond certain limits without depress- 
ing the protein-supply below the body needs for main- 
tenance. Fats are not as efficient protein-sparers as are 
carbohydrates. To be more explicit, fats and carbo- 
hydrates do not replace protein in proportion to their 
energy equivalents, carbohydrates being the more effi- 
cient. In brief, then, experience and science both indicate 
that carbohydrates are the most healthful, and physiologi- 
cally the most economical, source of a large proportion 
of the food energy. There is every justification for the 
relative abundance of starch foods in the rations of 
farm animals. 

272. Nutritive value of the gums. — ^The question has 
been raised as to whether the gums (pentosans) which 
exist so abundantly in many coarse foods and in some 
grain products like wheat bran are not inferior as sources 
of energy to the other more soluble carbohydrates. It 
has been observed that the sugars which result from the 
action of ferments on these bodies have, in some in- 
stances, not been oxidized, but have passed off in the 
urine as such. It appears that under normal and usual 
conditions this does not occur to any extent with herbiv- 
ora. Pentosans are present in all rations for farm 
animals, and we have no reason for believing that the 
pentose sugars are constant ingredients of their urine. 
MuccoUum and Brannon studied extensively the fate 
of various pentosans in the digestive tract of bovines. 
They found that these compounds are not equally diges- 
tible from all sources. Those from the corn, oat, and wheat 
plants were studied and the range of digestibility was 46 



FUNCTIONS OF THE NUTRIENTS 189 

to 67 per cent. The corn-plant pentosans were digested 
most fully and those from the wheat plant least so. 

Swartz concluded from extensive investigation that 
the water-soluble hemicelluloses are resistant to the 
action of enzyms and disappear from the digestive tract 
only in proportion as they are attacked by bacteria. 
Pentosans and mannans which are hydrolized by bacterial 
action w^ere found to be almost wholly digested, while 
galactans were largely excreted as such. In considering 
their digestibility the groups of hemicelluloses evidently 
must be considered separately. In any case, digestibility 
should not be considered as a measure of nutritive 
value. 

273. Relative importance of the nitrogen compounds 
of feeding-stuffs. — What is known as the crude protein 
of feeding-stuffs is the total nitrogen multiplied by the 
factor 6.25. As has been stated, protein as so estimated 
contains a variety of nitrogen compounds that are unlike 
in character and exist in various cattle foods in greatly 
unlike proportions. For example, a much larger part of 
the crude protein of coarse fodders and roots consists of 
amides than is the case with grains, the latter being cor- 
respondingly richer in true proteins. If, therefore, it is 
found that the true proteins differ from the amides in 
function and value, we have established one point of 
unlikeness between grain foods and roots or the coarse 
fodders. We have convincing proof that the true pro- 
teins are the main flesh-formers found in cattle foods. 
Are the amides such as glutamin and asparagin also flesh- 
formers? Earlier experiments with these compounds led 
to the conclusion that they may exercise a protective 
function toward the true proteins and thus reduce the 
minimum of such proteins necessary to satisfy the needs 



190 THE FEEDING OF ANIMALS 

of an animal under given conditions of production. Some 
of the more recent investigations indicate that the amides 
should be classed as to function with the true proteins, or, 
in other words, that they may take part in the synthesis 
of the proteins that are used constructively in the animal 
body though probably with not the same percentage of 
efficiency. Evidence exists, moreover, that the different 
amides are not of equal value. (See Par. 85.) 

274. Relative nutritive efficiency of the true pro- 
teins. — Notwithstanding possible function of the amide 
compounds in the synthesis of animal proteins, the true 
proteins of our cattle foods must be regarded as the main 
flesh-formers. There are, however, many true proteins 
which are unlike in their constitution. It is desirable 
to know whether these single proteins differ in nutritive 
value for specific purposes, like growth or milk forma- 
tion. Are the alcohol-soluble proteins, such as gliadin 
and zein of equal value with an albumin, a globulin, or 
casein? Reference has been made to the fact that while 
the cleavage products of these various proteins (amino 
acids), or what are called the building-stones, are to a 
great extent similar as to kind, these building-stones are 
not found in the same proportions in the several proteins, 
and with some proteins certain building-stones are lack- 
ing. The investigations of Mendell and Osborne, pre- 
viously mentioned, indicate great unlikeness in nutritive 
function and value. It is found, for instance, that the 
gliadin of wheat and rye does not function as does the 
casein in milk and that zein is particularly inefficient as a 
means of even sustaining life, and it is significant that 
the gliadin is deficient in lysine, and that zein is further 
lacking in tryptophane, whereas the proteins of the animal 
body contain both of these animo acids. (See Par. 85.) 



FUNCTIONS OF THE NUTRIENTS ' 191 

275. A single amino acid a limiting factor. — Evidence 
on this question is seen in experimental work carried on 
by Osborne and Mendell. These authors brought rats to 
full size and kept them in health when the diet contained 
18 per cent of casein. When the casein was reduced to 12 
per cent, growth fell below the normal. When reduced to 
9 per cent, growth was promptly limited by the protein 
factor. If, however, cystine was added to the 9 per cent 
of casein, the ration was rendered much more efficient 
for growth, showing that the presence of an insufficient 
quantity of this one building-stone was the limiting 
factor. Similar results were secured in experiments with 
edestin. When 15 per cent of the ration consisted of 
edestin, normal groA\i:h was secured, but not with 9 per 
cent. The addition of lysine to the 9 per cent of edestin 
caused an improvement. Lact-albumin was efficient 
because all the building-stones, including lysine and tr;>^to- 
phane, are relatively abundant in this protein. 

McCollmn has determined, through a series of experi- 
ments in which he fed single foods to pigs, the proportion 
of protein used by the animal for building protein tissue. 
His conclusions are as follows : p^^. ^^^^ 

deposited 

Oil meal proteins 16-17 

Wheat proteins 20 

Corn proteins 24 

Oat proteins 25 

Wheat germ 40 

Casein 45 

Skimmed mUk proteins 63 

The author also gives figures showing that the proteins 
of one food supplement those of another in producing 
more growth when the two foods are combined than when 
fed singly: 



192 THE FEEDING OF ANIMALS 

Per cent 
deposited 

Corn proteins 90 per cent, oil meal proteins 10 per cent . 31 
Corn proteins 75 per cent, oil meal proteins 25 per cent . 37 
Corn proteins 60 per cent, oil meal proteins 40 per cent . 32 

Those proteins are most efficient, evidently, whose 
building-stones correspond most nearly in proportion to 
those of animal proteins. 

276. Nutritive value of the gelatinoids. — ^The gelati- 
noids which belong to the class of non-proteins cannot 
be regarded as taking the place of proteins. It has been 
found that they protect protein from cleavage and thus 
make a minimum protein-supply more efficient but they 
do not function in the synthetical processes as the true 
proteins do. Gelatin also is lacking in certain building- 
stones, namely tyrosine, cystine, and tryptophane. This 
consideration of the protein compounds on the basis of 
their building-stones is a new and interesting point of 
view and leads to the conclusion that those proteins are 
most efficient for constructive purposes whose building- 
stones correspond in kind and proportion most nearly to 
those of the proteins in the animal body. 

277. Synthesis in the animal of phosphorus-beariipig 
proteins. — One interesting question which has been con- 
sidered is whether the nucleo-proteins and phospho- 
proteins which are found so abundantly in eggs and in 
milk must be supplied as such in the food, or whether 
they may be built up in the animal from the simple pro- 
teins and phosphates. If we could learn that the food 
must contain these peculiar proteins all ready for use, 
then we would have a valuable suggestion for feeding 
cows and poultry. It now seems that this is not the case. 
The sea salmon, which, during its stay up the river, is 
believed to take no food, undoubtedly produces large 



FUNCTIONS OF THE NUTRIENTS ' 193 

masses of eggs from the body substance, and it seems 
unlikely that so much nuclein as is needed exists in the 
flesh. If a cow gives thirty pounds of milk daily, nearly 
or quite a pound of casein must come from somewhere, 
and there is no evidence that any ordinary ration would 
contain so large a quantity of phospho-proteins of like 
constitution. Hens' eggs are rich in nuclein, beyond any 
amount which the food seems likely to supply. Experi- 
mental evidence supports these general inferences. 

278. The function of certain unidentified bodies. — 
An important addition to the science of nutrition is the 
recent demonstration that certain compounds are asso- 
ciated with animal foods which have a growth-promoting 
function and in the absence of which either artificial or 
natural foods fail to sustain growth and even life. (See 
Par. 118.) It has been known for some time that some 
such substance was associated with the shells of rice which, 
when given to animals afflicted with beri-beri from eating 
polished rice, would restore them to a normal condition. 
Substances of this class were named vitamines by Funk. 

An enlargement of the know^ledge of bodies of this 
class was led up to through studies by American 
investigators as to the relative nutritive value of single 
proteins. Heretofore the attention of investigators in 
animal nutrition has been focussed chiefly upon the con- 
structive and energy functions of the various classes of 
nutrients, and it was expected that when the proteins, 
carbohydrates, and ash compounds, supposedly necessary 
to complete nutrition, were all supplied to an animal, 
satisfactory results would be accomplished. It was dis- 
covered that, when there was fed a combination of puri- 
fied nutrients artificially prepared with great care and in 
accordance with the best knowledge of the needs of the 



194 THE FEEDING OF ANIMALS 

animal, growth was not secured. When, however, what 
was termed * 'protein free" milk was used in connection 
with such a preparation, normal growth resulted. This 
result, observed by Mendel and Osborn, led up to a 
series of investigations in which Hart and McCollum have 
taken a prominent part. It now appears from abundant 
data that two classes of growth-promoting substances 
exist, which have been termed Fat-soluble A and Water- 
soluble B, terms which are temporary until these bodies 
have been identified. The proof of the existence of these 
bodies has been illustrated as follows (McCollum): If to 
a mixture of purified proteins, carbohydrates, and salt 
mixtures containing all the salts found in the animal 
body there is added either a small amount of egg yolk 
or milk powder, growth proceeds normally; whereas the 
mixture of nutrients before such addition fails to produce 
growth. If the dried egg yolk is extracted with ether to 
remove the fat, the addition of the residue does not give the 
desired result. The addition of the fat alone also is shown 
to be futile. liP, however, there is added to the nutritive 
mixture along with the extracted egg-fat a water-extract 
of the fat-free yolk residue, growth is normal. Similar 
results occur with other substances, such as milk powder. 
This is the basis for the classification into Fat-soluble A 
and Water-soluble B, both of which are essential to 
growth. It appears that the milk of an animal which has 
been fed on purified nutrients fails to sustain her young, 
showing that these growth-promoting substances are 
transferred from the food to the mother's milk and are not 
synthesized within the body. 

It seems certain that the disease known as beri-beri, 
brought about by a restricted diet of polished rice, is due 
to the absence of one of these classes, and it is probable 



FUNCTIONS OF THE NUTRIENTS 195 

that pelagra, prevalent in the South where the diet of 
many individuals is considerably restricted, is due to the 
absence or insufficient supply of one or both of these 
classes. 

These accessory substances appear to be abundant in 
eggy milk, and the forage portion of many plants. Fat- 
soluble A being deficient in the body fats of animals and 
absent from the fats or oils of many species of plants. 
The knowledge of the presence or absence of these growth- 
promoting substances in cattle foods will undoubtedly be 
enlarged as investigation proceeds. 

It is shown in experiments by Hart and McCollum 
that when the rations of animals were restricted to a single 
'plant, that the wheat germ contains a toxic body. Ani- 
mals fed wholly on the corn plant or its products developed 
normally and produced young. Those fed on the wheat 
plant or its products, without the addition of other food, 
failed to make satisfactory gro\\i:h and to produce vigor- 
ous young. Similar results were obtained with wheat 
products when fed to swine. Such results with the wheat 
plant were evidently not due to a lack of nutrients but 
investigation showed that the operating cause was a 
poisonous principle located in the fat of the wheat, this 
principle being removed when the wheat oil was extracted. 
We have here, then, an example of a toxic body con- 
tained in one of the most common of our feeding-stuffs, 
the effect of which has been less observed because wheat 
by-products have constituted only a portion of the food 
of the animal. 

279. Relation of production values to profit from 
feeding animals. — ^The production from a given quantity 
of food varies greatly under unlike conditions. It can 
scarcely be doubted that the proportion of the available 



196 THE FEEDING OF ANIMALS 

nutrients which are consumed, that is, burned as fuel, 
increases as the ration increases above what is needed 
for maintenance, and inversely the proportion of the 
nutrients stored in the body as flesh and fat undoubtedly 
is less the greater the quantity fed is in excess of the 
demands for maintenance. A large excess over mainte- 
nance is relatively less efficient than a small one in the 
production of flesh or milk. There comes a point where 
additional food produces no additional gain, but only 
additional consumption. The age of the growing animal 
and the condition of a fattening animal also modify the 
efficiency of the food for production purposes, as does 
individuality, and with a cow the stage in the period of 
lactation. With all these variations no averages are pos- 
sible which express with any definiteness fixed production 
values for the different nutrients. 



CHAPTER XI 

LAWS OF NUTRITION 

The preceding pages have been devoted to a 
discussion of the origin of cattle foods, what they are 
in substance, how their nutrients are made available and 
how used. So far no attempt has been made to bring 
together in a concise form what may be called the funda- 
mental principles or laws of nutrition. It is desirable, how- 
ever, before passing to the consideration of the practice 
of cattle-feeding, to simimarize the principles on which 
the science of cattle-feeding is based. 

280. All energy and building-material applied to the 
maintenance and growth of the animal body come from 
the food, water, and oxygen being included in this term. 
The animal originates neither energy nor matter. 

281. Only that portion of the food which is digested, 
i. e., that which is rendered soluble and diffusible by the 
digestive fluids so that it passes into the blood, is avail- 
able for any use whatever. 

282. The imutilized food and the wastes pass from the 
body in several directions. The undigested part mainly 
constitutes the solid excrement or feces. The lu'ea and 
other nitrogenous compounds which are the unoxidized 
portion of the protein, pass out wholly in the urine. All 
digested nitrogen not stored is found here. The carbon 
dioxid is eliminated through the skin and lungs, chiefly 
the latter, and water is disposed of through the kidneys, 
skin, and lungs. 

(197) 



198 THE FEEDING OF ANIMALS 

283. The digested food is used in two general directions, 
(a) for the production of energy and (6) for constructive 
purposes. 

(a) The food energy is made available through com- 
bustion, i. e., the oxidation of the carbon compounds of 
the food to simpler substances, carbon dioxid and water, 
thus liberating the energy stored in the plant during its 
growth. Protein is never fully oxidized, but carbohydrates 
and fats may be. All the organic nutrients may be oxi- 
dized to produce energy, the phycological energy values 
of protein, carbohydrates, and fats being approximately 
as 1, 1, 2.25. The larger part of the energy used by farm 
animals comes from the carbohydrate portion of the food. 
This liberated energy finds expression in the animal 
organism in various ways, as heat, mechanical energy or 
motion, and chemical transformations. The total energy 
of food is never all available to the animal because of a 
loss in the excreta and gases. Moreover, the productive 
energy is much less than the available energy, because 
much energy is used in the work of appropriation of the 
food. 

(h) The food compounds are used for constructive 
purposes, either without changing their general charac- 
ter, as, for instance, the building of muscular tissue from 
the plant proteins, or they may be reorganized into bodies 
of a very different character, as in the formation of 
animal fats from starch and sugar. Protein is used to 
construct muscular tissue, in fact, all the nitrogenous 
parts, and is a source of fat. Carbohydrates can only be 
used constructively for the formation of fat, and the same 
is true of food fats or oils. Mineral matter is needed for 
the formation of bone, enters into the constitution of the 
soft parts, and has important metabolic functions. 



LAWS OF NUTRITION ' 199 

284. The matter of the digested food, including water 
and oxygen, is exactly equal to that stored in the body or 
in milk, or both, plus that in waste products — feces, 
water, carbonic acid, and urine solids. Such a balance 
may not be maintained for any particular day, but will 
ultimately be foimd to exist. 

285. Under given conditions of species, sex, climate, 
and use, a definite amount of digested organic matter is 
necessary to maintain a particular animal without gain 
or loss of body substance. This means simply that tis- 
sue wastes must be replaced, and the fuel-supply must 
be kept up. 

If the animal receives no food, or less than the amount 
needed for maintenance purposes, tissue waste and the 
production of energy do not cease, but go on wholly or 
in part at the expense of the body substance. 

286. Food supplied above a needed maintenance quan- 
tity may be utilized for the production of new substances 
or work or may be eliminated in part increasing the 
waste. Within limits, both things generally occur. In 
the proper sense of the term, no production ever occurs 
without an excess of food above maintenance require- 
ments. Milk formatiori may sometimes go on at the 
expense of the body substance, but with proper feeding, 
milk, flesh or muscular work are produced at the expense 
of food supplied in excess of that needed for maintenance. 

287. Regard must be had to the supply of particular 
nutrients as well as of total food. Even with an animal 
doing no work and giving no milk a certain amount of 
protein will be broken up constantly into urea and simi- 
lar compounds, an amount which will be withdrawn from 
the body tissues to the extent that it is not supplied by 
the food. In addition to this, a milch cow, for instance. 



200 THE FEEDING OF ANIMALS 

must have protein for the forraation of the nitrogen com- 
pounds of the milk, or a steer for the growth of flesh, in a 
quantity proportional to the production, and food must 
supply it. There is, therefore, a minimum supply of pro- 
tein, which, in a particular case, is necessary for the 
maintenance and for constructive purposes, less than 
which ultimately diminishes production to the extent of 
the deficiency, or else requires the use of body tissue. 

288. The different classes of nutrients are to some 
extent interchangeable in their functions. That is to say, 
all the organic nutrients may be burned to supply energy. 
Protein may be so used even to withdrawing it from the 
purposes to which it is necessary unless the carbohydrates 
or fats are sufficient to protect it from being consumed as 
fuel. A proper supply of the non-nitrogenous nutrients 
is required, therefore, to insure the application of the 
necessary minimum of food protein to its peculiar uses. 
The carbohydrates and fats are the physiologically eco- 
nomical source of the main part of the energy used by 
farm animals. 



CHAPTER XII 
SOURCES OF KNOWLEDGE 

The foregoing chapters embody many statements of 
principles and facts which have been made positively 
and without modification. To quite an extent these 
are based upon the conclusions of scientific men, i.e., 
conclusions which have been reached after such study 
of the problems involved as is competent to secure ac- 
curate information. In some cases this study has been 
severe and long continued, having been carried on by 
the use of methods and apparatus capable of the most 
precise measurements. Moreover, in the investigations 
of science an effort has been made to proceed logically, 
so that the results attained shall not be fallacious. Not- 
withstanding the fact that a great deal of our knowledge 
is the result of an earnest and impartial search after 
truth, under conditions especially favorable to its dis- 
covery, many persons are disposed to give more credit to 
traditions and conclusions of practice than to the care- 
fully prepared verdicts of science. It may not be out of 
place, therefore, to present in this connection some of the 
considerations and methods which have to do w^th the 
acquisition of knowledge concerning animal nutrition, 
for this may aid us to appreciate the value of well-estab- 
lished facts and to exercise caution in accepting the 
verdicts either of science or of practice before they are 
thoroughly justified. 

There are three general ways in which we may be 

(201) 



202 THE FEEDING OF ANIMALS 

said to have acquired knowledge in regard to feeding 
animals : 

1. The observation of ordinary practice. 

2. Practical experiments, so called. 

3. Scientific investigation. 

289. Conclusions from feeding practice. — Until within 
recent years, the practice of cattle-feeding has been 
entirely governed by the conclusions drawn from ordi- 
nary practice. Among the many men engaged in animal 
husbandry, certain ones possessed of more than average 
powers of observation and business ability have secured 
good results with certain feeding-stuffs and methods of 
feeding, and their practice has been accepted by their 
neighbors with no further demonstration than that these 
successful farmers sold fat cattle and obtained large 
returns from the dairy. During the centuries that man 
has had domestic animals under his care, certain results 
have appeared to follow from certain systems of feeding 
or the use of certain foods, and upon these so-called 
practical observations the feeder has built his creed. 

In these ways there have come to be accepted, some- 
times locally and sometimes generally, standards of 
feeding as to quantity, kind of ration, and times of feed- 
ing. At the same time, it was necessary only to attend 
a farmers* convention fifty years ago to become con- 
vinced of a great variety of opinions as to the best 
methods of practice. In fact, opinion was the court of 
last resort. There were then no known, well-estab- 
lished fundamentals to which appeal could be made as 
a basis for discussion. While many false notions were 
entertained, many of the beliefs then prevailing were 
undoubtedly correct or contained a germ of truth. It 
is generally safe to assume that when an opinion is 



SOURCES OF KNOWLEDGE 203 

widely and persistently held it is not altogether with- 
out reason or foundation. It is often the expression, in 
more or less correct terms, of some important principle. 
No one should lightly turn aside from widespread tra- 
ditions and convictions in regard to any line of practice. 
A knowledge of the precepts governing the feeder's art 
that are the accumulation of experience in the care of 
animals is to be respected and is, to a great extent, essen- 
tial to successful practice. It is also true that little sub- 
stantial progress can be realized in any art if its under- 
lying truths are not understood, for when this is the case 
the results of experience under one set of conditions do 
not serve as a guide under circumstances entirely different. 

290. Practical feeding experiments. — ^With the advent 
of modern science and of the efforts to utilize it in agri- 
culture, an attempt has been made to search for impor- 
tant truths more systematically, an effort undertaken 
chiefly by experiment stations. As one means of gain- 
ing knowledge, these institutions, and to some extent 
private farmers, have conducted many so-called practical 
feeding experiments in order to verify present beliefs, 
test theories, and solve existing problems. The relative 
value of various feeding-stuffs and rations for producing 
growth and milk and the influence of different fodders 
and grain foods upon the quality of the product have 
been the subjects of numerous feeding tests. Much 
valuable information has been secured in this way, but 
there has not always been a full recognition, even by 
experiment stations, of the limitations which should be 
observed in drawing conclusions from this manner of 
experimentation. 

291. Inconclusiveness of ordinary feeding experi- 
ments. — In order to view this matter more in detail, let us 



204 THE FEEDING OF ANIMALS 

consider experiments in testing rations for growth and 
milk production. The usual method of procedure with 
such feeding trials is either to feed two lots of animals 
on the rations to be compared and note the compara- 
tive growth or milk yield, or to feed the same lot 
on one ration for a time and then change to another 
ration. 

If these tests are made with growing or fattening 
animals, the increase in live weight is taken as the meas- 
ure of the relative efficiency of the rations compared. 
It should be said of these experiments that their appar- 
ent verdict is to be accepted with great caution, and 
definite conclusions are not justified until repeated 
extended trials of two rations or of two systems of feed- 
ing, made with the use of all possible precautions against 
error, and under a variety of conditions, give uniform 
and consistent results in the same direction. There are 
several reasons why this is so, the main one being that 
the increase in the weight of an animal is an uncer- 
tain measure of actual growth. Variations in the con- 
tents of the alimentary canal due to the irregularity of 
fecal discharge and to a lack of uniformity in the water 
drank may cause temporary variations in the live weight 
of considerable magnitude. Moreover, the nature of the 
growth of body substance is revealed neither by the mere 
weighing of an animal nor by his general appearance. 
Even if the changes in weight are due to an increase of 
body tissue, this may be more largely water in one case 
than in another, so that the real contribution of the food 
to the dry substance of the body may not be shown. 
Nor is the character of the solids deposited in the animal 
discovered by merely weighing him. In fact, by such 
practical experiments we simply learn that one set of 



SOURCES OF KNOWLEDGE ' 205 

animals has gained more or less pounds of weight than 
another set, but the why and the how are not explained. 

Practically the same considerations pertain to feed- 
ing tests for milk production. When the milk flow from 
one ration is larger than from another, we can easily 
satisfy ourselves as to the comparative yield of milk 
solids, which is the real test of such production; but we 
are not able to decide whether the cow either may not 
have contributed to the milk secretion from the substance 
of her own body, or may not have gained in body sub- 
stance, the extent of such loss or gain being greater, 
perhaps, with one ration than with another. 

Even if these uncertainties did not exist, we have 
the still greater disadvantage of not learning by this 
means why a particular combination of feeds has superior 
qualities for causing growth or sustaining milk secretion. 
The mere data showing that an animal ate so many 
pounds of food and produced so many pounds of beef or 
milk are important business facts, but they reveal noth- 
ing concerning the uses of the several classes of nutrients 
and of themselves furnish slight basis for developing a 
rational system of feeding. We must somehow learn the 
function of protein, carbohydrates, and fats in main- 
taining the various classes of animals and the real effect of 
varying the source, quantity, and relative proportions of 
these nutrients before we can draw safe general conclusions. 

292. Chemical and physiological studies. — ks> pre- 
liminary to more comprehensive and convincing methods 
of investigating feeding problems, there has been going 
on during many years a necessary study of the compounds 
which are found in plants and animals. Much has been 
learned about the ultimate composition and the consti- 
tution of the proteins, carbohydrates, and fats, their 



206 THE FEEDING OF ANIMALS 

physical and chemical properties, the compounds into 
which these bodies break under certain conditions, the 
chemical changes to which they are subject through cer- 
tain agencies, and their relation to one another. Investi- 
gations along these lines have for years occupied the 
time of some of our ablest scientists, and, while such 
researches when they were conducted may have seemed 
to the extreme utilitarian to be of little value, we now see 
how directly they are contributing to human progress 
and welfare. 

To the above information has been added through 
physiological investigations a knowledge of the ways in 
which the several food compounds are transformed in 
digestion and in other metabolic changes, the avenues 
along which these compounds travel, and the ways in 
which their products of decomposition are discharged 
from the animal organism. We have learned how to dis- 
tinguish between the digested and undigested food, have 
demonstrated that all the nitrogen of the decomposed 
proteins passes off in the urine, have measured the com- 
bustion of the nutrients and have learned how to strike a 
balance between the income and outgo of the animal - 
body. It is now possible to determine with reasonable 
accuracy just how much substance is retained or lost 
from the body of the experimental animal while eating a 
given ration, and what is the nature of the gain or loss. 
Very recently means have also been devised for measur- 
ing the heat given off by a man or an animal in order to 
ascertain the actual physiological values of different 
feeding-stuffs. 

293. More accurate methods of investigation than 
practical feeding tests. — In applying the principles and 
facts of chemistry and physiology, the first advance from 



SOURCES OF KNOWLEDGE ' 207 

the ultra-practical feeding experiment in the direction 
of an accurate history of what occurs when the animal 
is eating a particular ration is the measurement of the 
digested nutrients and the determination of the gain or 
loss of nitrogen. This is accomplished, as heretofore 
stated, by ascertaining the quantity of various com- 
pounds eaten and the amount of the same in the feces, 
the difference being the digested portion. The urine is 
also collected, and if the nitrogen in it is less or more than 
that in the digested protein, then the animal is either 
gaining or losing nitrogenous body substance, unless 
the measurement is with a milch cow, when the nitrogen 
in the milk must be taken into account. By an experi- 
ment conducted in this way, with careful and continued 
weighings of the experimental animal, it is possible to 
secure a probable relation between a unit of digested dry 
matter and a unit of production. Such a method has been 
used to determine what is a maintenance ration for ani- 
mals of several classes, and in those cases where the 
experiments have been continued for a sufficient length 
of time and have shown on repetition a reasonable agree- 
ment, we are justified in accepting the results as a close 
approximation to fact. When a ration keeps an animal in 
nitrogen equilibrium for one or more months and no 
material gain or loss of weight occurs, we may safely 
regard it as approximately a maintenance ration under 
the conditions involved. Experiments of the same kind 
are equally useful in testing the productive power of 
various food combinations, and whenever by such con- 
tinued tests one ration shows no superiority over another, 
it is safe to assume that no differences exist which would 
be especially important to the farmer's pocketbook. This 
may be accepted as a business fact. 



208 THE FEEDING OF ANIMALS 

294. Studies of food sources of animal fats. — Another 
class of experiments somewhat more severe in their 
requirements are those designed to give information as 
to the relation between the constituents of the food and 
the growth of the various tissues in the animal body or 
the formation of milk solids. The experiments conducted 
by Lawes and Gilbert on the formation of fat with swine 
may be cited in illustration of the methods used. These 
were planned so as to learn the amounts of digested pro- 
tein, carbohydrates, and fat consumed by the animal and 
also the quantities of protein and fat stored in the body 
during a given period. "In experiment No. 1, two pigs 
of the same litter, of almost exactly equal weight, and, so 
far as could be judged of similar character, were selected." 
One was killed at once and its composition determined, 
and the other was fed for ten weeks on a fattening ration 
of known composition and then slaughtered and analyzed. 
The quantity of protein and fat which the pig's body had 
gained during the ten weeks as ascertained from the com- 
position and weight of the two pigs was then compared 
with the food-supply of similar compounds. It was 
assumed that a pound of food fat could produce a pound 
of body fat and that 51.4 per cent of all the protein not 
stored in the body as such could be used for fat formation. 
Even with the most liberal allowances it was found that 
the protein and fat of the food could not possibly have 
been the sole source of the new body fat, thus forcing the 
conclusion that the carbohydrates are fat-formers. Prac- 
tically the same plan has been followed in studying the 
source of milk-fat. Several cows were fed on carefully 
weighed and analyzed rations extremely poor in fat, and 
the amount and composition of the feces, urine, and milk 
were ascertained during sixty to ninety days. The fat 



SOURCES OF KNOWLEDGE - 209 

digested from the food and the theoretical fat equivalent 
of the decomposed protein as measured by the urine 
nitrogen were charged up against the milk-fat, and a large 
quantity of the latter could be accounted for only as 
having had its source in carbohydrates. 

Another method of investigating fat formation has 
been used with dogs. It is w^ell known that when an 
animal is deprived of food the expenditure of energy 
by the body is maintained at the expense of body sub- 
stance. Both muscular tissues and fatty substance are 
broken down and used in this way, the latter being 
regarded as furnishing the most natural and available 
supply of fuel. It was found in the case of dogs that 
after a certain number of days of starvation there oc- 
curred a sudden and large increase in the waste of nitro- 
gen compounds as shown by the urine excretion, the 
explanation for this being that the body fat had become 
exhausted and a demand was at once made upon the 
protein tissues for the necessary supply of energy. As 
soon as this rise of nitrogen waste appeared, then the 
dog was allowed to eat, and whatever fat was found in 
the body at the end of the feeding-period was regarded as 
having been formed from the food taken after the star- 
vation period. If, for instance, the ration was wholly 
protein and fat was found to have become deposited in 
the body, this was regarded as proof of the formation of 
fat from protein. Such experiments as these have not 
always been conclusive, although they are regarded by 
some scientists as having furnished proof that protein 
may be a source of fat. 

295. The respiration apparatus. — After all, the investi- 
gations of the kinds described fail to furnish data so 
accurate and so complete as are necessary for entirely 

N 



210 THE FEEDING OF ANIMALS 

safe conclusions. In every instance, one or more assump- 
tions are involved where definite proof is not furnished. 
Nothing short of a complete record of the income and 
outgo of the animal organism during the experimental 
period is conclusive evidence as to whether there has been 
a gain or loss of body substance and what is the kind and 
extent of the growth or waste. The securing of such a 
record is an expensive and laborious task. It requires not 
only complete information in regard to the quantity and 
composition of the food, but also an acccurate measure- 
ment of the excreta, including the feces, the urine, the 
respiratory products, and the matter given off through 
the skin. Such measurements are taken by means of a 
respiration apparatus, a costly and complicated mechan- 
ism, a detailed description of which would be of little use 
to most readers. It is sufficient to state that this appa- 
ratus makes possible the collection and analysis of all the 
excretory products, whether solid or gaseous. The 
experimental man or animal lives in a closed chamber 
into which is introduced food and fresh air and from 
which is pumped the vitiated air, the water and carbon 
dioxid of which are absorbed and weighed. 

All conclusions drawn from experiments with the 
respiration apparatus are based largely upon the in- 
come and outgo of nitrogen and carbon. As carbon 
is a constituent of all possible compounds of the ani- 
mal body except the mineral, it is certain that when 
the body gains in carbon it gains in organic substance 
of some kind, and if it loses in carbon there is a waste 
of organic body substance. The general character of 
the gain or loss can be determined by the nitrogen bal- 
ance. If more nitrogen is taken in by the experimental 
animal than is given off, it is clear that the nitrogen 



SOURCES OF KNOWLEDGE , , 211 

compounds of the body have received an accession. 
Knowing as we do the proportions of nitrogen and car- 
bon in the various tissues of the animal, we can calculate 
how much of the gain or loss of carbon belongs in the 
nitrogenous substance deposited or w^asted. If more 
carbon is gained or lost than can possibly be associated 
with the nitrogen gained or lost, then there has been a 
gain or loss of fat, because protein and fat being the main 
constituents of the animal carcass, any considerable 
retention of carbon must be in one of these forms. If 
there has been nitrogen equilibrium, all excess or deficit 
of carbon belongs to a deposit or waste of fat. By such 
searching methods as these, it is possible to ascertain 
with a good degree of accuracy how food is used and what 
quantity and kind of nutrients are needed in maintain- 
ing an animal under given conditions. 

296. Detennination of energy values. — ^\Ve have 
reached a point in our study of animal nutrition where 
we realize that food values are to some extent commen- 
surable with energy values and that it is desirable to 
know the energy product of different compounds and 
feeding-stuffs. Moreover, we cannot possess sufficiently 
full knowledge concerning the energy needs of the several 
classes of animals until we have measured energy use in 
terms of heat given off under the various conditions of 
work and of production. The mere determination of the 
income and outgo of the animal body does not neces- 
sarily measure energy needs or use. We may go so far 
as to ascertain that a certain amount of carbon from a 
certain source was consumed in a given time, but from 
this alone we do not learn the extent to which this com- 
bustion has supported the internal and external work 
of the body. 



212 THE FEEDING OF ANIMALS 

297. Calculation of the energy value of a ration. — 
Three methods may be adopted for determining the 
energy expenditure by an animal eating a given ration. 
The one of these most easily carried out is largely a 
matter of mathematical calculation. By the use of 
average digestion coefficients it is possible to ascertain 
approximately the amounts of digestible protein, carbo- 
hydrates, and fats contained in any ration which is 
apparently accomplishing a desired result. We have 
learned from previous determinations what are the calorific 
values of individual compounds such as albumin, starch, 
sugar, stearin, and olein and these compounds are assumed 
to represent the energy value of the classes of nutrients to 
which they belong. If, then, we multiply the calculated 
quantities of digestible protein, carbohydrates, and fats by 
their respective assumed energy factors, we get a number 
which has been taken as an expression of the available 
energy of the ration under consideration. This method 
must now be regarded as greatly inaccurate, because 
the metabolizable energy of the digestible material 
of feeding-stuffs is found to be much below the calorific 
value of the pure nutrients to which energy measure- 
ments have been applied. See Tables XXVIII and 
XXXIII. The older theoretical method by computation 
might give the relative, but not the actual, units of 
metabolizable energy in the several feeding-stuffs, for the 
results by means of combustion in a Zuntz calorimeter 
of pure nutrients do not measure physiological results 
with complex mixtures. 

298. Energy value of digested nutrients. — A second 
method, which is probably a step in the direction of greater 
accuracy, is to determine by the use of a calorimeter the 
heat units of the ration and also of the urine and feces. 



SOURCES OF KNOWLEDGE ' 213 

The differences between the food heat units and those 
found for the excreta might seem to represent the energy 
value of that portion of the ration digested by the animal. 
This would be an accurate measurement of the available 
or metabolizable energy of the ration if it were not for the 
loss of unoxidized gases, chiefly methane, which contrib- 
ute nothing to the maintenance of the animal. Accurate 
work requires that these gases be measured. But even 
then it does not appear to what extent the digested 
nutrients have been oxidized with a corresponding radia- 
tion of heat or whether there has been a gain or loss of 
body substance. If there has been a gain of body sub- 
stance, then the ration is productive, but if there has been 
a loss of body substance, then the ration is below the 
required standard for the maintenance of the particular 
animal under investigation. In a study of energy rela- 
tions, it is therefore even more necessary to resort to a 
respiration apparatus of some sort than in determining 
food balances. We must learn the actual extent of the 
food combustion w^hich occurs if we would have all the 
data necessary for measiu-ing energy used, and here we 
come to the third and most accurate method of determin- 
ing energy expenditure, viz., experiments with a respira- 
tion apparatus. 

299. Measurement of food combustion. — ^There are 
two general ways of ascertaining the extent to which 
food is burned by any living organism. One is to measure 
the products of combustion and the other is to measure 
the amount of oxygen used. It is self-evident that no 
combustion can occur without the use of oxygen, and so 
if the experimenter is able to learn just how much of this 
element is taken up in uniting with the carbon and hydro- 
gen of the food, he has a direct and accurate means of 



214 THE FEEDING OF ANIMALS 

measuring actual energy production. The older forms of 
respiration apparatuses simply allowed an estimation of 
the carbon dioxid and water given off by the animal. 
How much of the water was formed by the oxidation of 
the hydrogen of the food and how much was simply 
evaporated from the store taken in as water, it was 
impossible to know by direct determination. This could 
only be calculated. The carbon dioxid was, on the other 
hand, a direct and accurate measure of the combustion 
of carbon. Later devices, as, for instance, the one used 
by Zuntz, allow a direct determination, not only of the 
products of combustion, but of the oxygen absorbed by 
breathing. This method of work seemed to have advan- 
tages, as one measurement not only checks the other, but 
makes it possible to ascertain the actual oxygen consump- 
tion during any given period of the experiment, as, for 
instance, when the animal is at rest, when masticating 
food, or w^hen performing a given amount of external 
work. In this way, Zuntz made his masterly demon- 
strations of the differences in ox;v^gen use with different 
foods during the period of mastication. 

300. Respiration calorimeter. — None of the older 
apparatuses, whether allowing the determination of 
oxygen consumption or not, measured the heat radia- 
tion from the animal body, or, in other words, the amount 
of energy actually evolved from internal combustion. 
Professors Atwater and Rosa first devised a respiration 
apparatus which was at the same time a calorimeter. 
The quantity of heat radiated from a man or other 
animal confined in this calorimeter is absorbed by a 
known volume of water and is thus determined. This 
is a great advance towards certainty, because direct 
measurements of the energy production of a ration are 



SOURCES OF KNOWLEDGE - 215 

thus made possibte and the necessity for theoretical 
assumptions is largely removed. 

301. Study of the efficiency of individual proteins. — 
The type of investigation in animal nutrition upon which 
much emphasis is now placed is a study of the function 
and relations of individual compounds. The proteins 
have been especial objects of studies of this kind, studies 
w^hich have been made possible through the isolation and 
identification of many individual vegetable and animal 
proteins. The general plan of w^ork has been to feed only 
one well-identified protein in connection with a sufficient 
supply of all the other nutrients necessary to maintenance 
and growth. In this way it has been demonstrated that 
the individual proteins are greatly unlike in their nutritive 
value and relations, it being found that some will not 
sustain growth or even maintenance, while other single 
proteins constitute an efficient protein-supply for any 
known protein use. 

It is already made clear to the reader, doubtless, that 
the demonstration of facts and principles in the domain 
of animal nutrition is exceedingly difficult. It should 
be equally clear that when conclusions are reached in ways 
which have been briefly described, they are worthy of 
respect and should have greater weight than the neces- 
sarily imperfect observations of common practice. Science 
often errs in her deductions, but the efforts of her workers 
are constantly directed toward the elimination of false 
conclusions, so that unsound theories are not likely to be 
accepted for a great length of time. 



PART II 
THE PRACTICE OF FEEDING 



CHAPTER XIII 
CATTLE FOODS— NATURAL PRODUCTS 

The number of cattle foods now available for use 
is very large, and the list appears to be constantly in- 
creasing. Not only have several fodder plants been 
added to those formerly grown, but we have now a great 
variety of waste products from the manufacture of oils, 
starch, and human foods that are being placed upon 
the market as feeding-stuffs. At one time farmers pro- 
duced all their cattle ate, and this was done without 
going outside a very limited list of forage plants and 
grains. All this is changed, especially in the older, more 
thickly-settled portions of the United States, so that 
considerable knowledge is now needed regarding the 
composition and specific characters of the numerous 
kinds of feeding-stuffs if they are to be used intelligently. 

302. Classification of cattle foods. — It will aid in 
discussing this branch of our subject if we first note the 
divisions into which the materials used for feeding farm 
animals are grouped. There is more than one basis upon 
which it is possible to make these divisions — botanical 
relations, the portion of the plant used, whether stem or 
fruit, and chemical composition. As a matter of fact, all 
these and other distinctions are involved in the classi- 
fication of the cattle foods in common use at the pres- 
ent time. 

The feeding-stuffs of vegetable origin are generally 
divided into four classes: (1) Forage crops, consisting 

(219) 



220 THE FEEDING OF ANIMALS 

of the stem and leaves of herbaceous plants, either in 
green or air-dry condition, to which is attached in some 
cases the partially formed or wholly mature seed or 
grain; (2) roots and tubers, or the thickened under- 
ground portions of certain plants; (3) seeds or grains; 
(4) parts of a plant which are the by-products from the 
removal of other parts by some manufacturing process. 
These are the commercial by-product feeding-stuffs. 

FORAGE FOODS 

303. Classes of forage crops. — ^The valuable forage 
plants of the United States belong mostly to two families, 
the grasses (Graminese) and the legumes (Leguminosae). 
June grass, red-top, timothy and the cereal grain plants 
are types of the former; and the clovers, alfalfa, 
the vetches, and peas, of the latter. Whether in the 
pasture or in tilled fields, few plants outside of these 
divisions contribute materially to the supply of high- 
class fodders. The most essential difference between the 
members of these two families of plants when considered 
as feeding-stuffs is the larger proportion of nitrogen com- 
pounds in the legumes. It is characteristic of all legumes 
that their proportion of protein is high as compared with 
any other forage crops, and for this reason they are 
greatly prized on dairy farms. The fact that they are 
regarded as increasing materially the nitrogen supply 
of the farm from sources outside the soil also adds to 
their value. 

304. Green vs. dried fodders; conditions of drying. — 
Nearly all of the herbaceous plants that are grown for 
consumption by farm animals may be fed either in a green 
or dry state. Oats, maize, clover, alfalfa, and other spe- 



CATTLE FOODS— NATURAL PRODUCTS ' 221 

cies which serve so useful a purpose as soihng crops for 
summer feeding are also dried that they may be success- 
fully stored for winter feeding, although mazei, and, to 
some extent, other crops, are now preserved in a green con- 
dition through the process of ensilage. (See Pars. 37-41.) 

305. Effect of drjdng fodders. — The advantages and 
disadvantages of green as compared with dry fodders 
have been much discussed. It is safe to assert that the 
compounds of a dried fodder which has suffered no 
fermentation are practically what they were in the 
green, freshly cut material, excepting that nearly all of 
the water contained in the green tissues has evaporated 
and that in drying there is a possible loss of an imper- 
ceptible amount of volatile compounds, whose presence 
in the plant affects its flavor more or less. It is certain 
that curing a plant generally diminishes its palatable- 
ness and increases its toughness, or its resistance to 
mastication, although with many crops, as for instance 
the early cut native grasses, these changes do not affect 
nutritive value to a material extent. There is no ques- 
tion but that the mere matter of being green or being dry 
has very little influence upon the energy value of a fodder 
or upon the extent to which it wdll sustain growth or milk 
formation. We must, however, take into account the 
desirability of the highest state of palatableness. 

306. Losses through curing fodders. — Drying fodders 
under perfect conditions is not always possible. The 
long-continued and slow curing of grass in cloudy weather, 
especially when there is more or less rainfall, is accom- 
panied by fermentations that result in a loss of dry sub- 
stance more or less extensive, and which oxidize some of 
the most valuable compounds, principally the sugars. 
The tissues of certain plants, maize for instance, are so 



222 THE FEEDING OF ANIMALS 

thick that rapid curing in the field is never possible, and 
fermentative changes are unavoidable. It is probable 
that maize fodder and stover are never field-dried with- 
out a material loss in food value, for it is found that even 
when the stalks are finely chopped, drying by artificial 
heat is necessary to a complete retention of the dry mat- 
ter. The extent of the loss from curing fodders must be 
very variable. So far as we know, grass, which in "good 
haying weather" is well stirred during the day and packed 
into cocks over night so as to avoid the action of heavy 
dew, suffers practically no deterioration, while dull 
weather or rain may cause a serious loss. It is doubtful, 
however, whether night exposure during good weather is 
sufficiently injurious to justify the expense of cocking 
partially cured hay. On the other hand, the economy of 
using hay caps during unfavorable weather is without 
question. The over-drying of hay before raking into 
winrows and "bunching*' so as to cause a loss of the leaves 
and the finer parts through brittleness may be as wasteful 
as under-drying and the consequent fermentation. Over- 
dried hay does not pack well in the mow and is less pala- 
table. The leguminous hays, such as clover and alfalfa, 
are expecially subject to loss from over-drying before 
handling. Fodder crops, if dried at all, should be dried 
to such a percentage of moisture that they will not "heat'* 
to discoloration after being packed in large masses and 
lose value from the same general causes that operate in 
field-curing under bad conditions. (See Par. 45.) 

307. The harvesting of forage crops. — ^The result to be 
achieved in the growing of forage crops is the produc- 
tion on a given area of the maximum quantity of digesti- 
ble food materials in a palatable form. The age or period 
of gro'\^i:h at which a forage crop is harvested is an impor- 



CATTLE FOODS— NATURAL PRODUCTS 



223 



tant factor in this relation and may affect the product in 
three ways: (1) in the quantity of material harvested, 
(2) in the composition of the crop, and (3) in the palata- 
bleness of the resulting fodder. In discussing this ques- 
tion we must recognize the fact, first of all, that in these 
respects no general conclusion is applicable to all crops. 
What would be wisest in the management of the meadow 
grasses might be wasteful in handling the legumes, and 
especially so in harvesting maize. 

308. Maximum yield of forage crops at maturity. — 
It is safe to assert that in general the maximum quan- 
tity of dry matter is secured when forage crops are 
allowed to mature fully and ripen. The only exception 
to the rule is found in the legumes such as the clovers 
and alfalfa, where at maturity the leaves unavoidably 
rattle off and are lost, either before or during the process 
of curing. The fact that growth of dry matter takes 
place up to the time of full maturity is well illustrated by 
the results of experiments conducted on the farms of the 
Pennsylvania State College, the New York Experiment 
Station, and the University of Maine, in cutting timothy 
grass, clover, and maize at different stages of growth. 
These results are summarized in the accompanying tables : 



Table XLIV. Timothy Grass 


(Yield of 


Dry Hay to the Acre) 


Stage of growth 


Results in Maine 


Results in Pennsyl- 
vania — two farms 


Av. 3 years 
1878-1880 


1 year 
1889 


Av. 2 years 
1881-1882 


Nearly in head 

Full bloom 

Out of bloom or nearly ripe 
Ripe 


Pounds 

3,720 
4,072 
4,136 
3,832 


Pounds 

4,225 
5,086 


Pounds 

2,955 
3,501 







224 



THB FEEDING OF ANIMALS 



Maize for Silage (Yield of Dry Matter to the Acre) 



Stage of growth 



Tasseled to beginning of ear .... 
Silked to some roasting ears .... 
Watery kernels to full roasting-period 

Ears glazing 

Glazed to ripe 



New York 


Maine 


1889 


1893 


Pounds 


Pounds 


1,620 


3,064 


3,080 


5,211 


4,640 


6,060 


7,200 


6,681 


7,920 


7,040 



Red Clover (Yield of Dry Matter to the x\cre) 



Stage of growth 



Pennsylvania 
1882 



In full bloom 
Some heads dead 
Heads aU dead . 



Pounds 

3,680 
3,428 
3,361 



These data are convincing testimony as to the growth 
of dry substance in certain forage crops up to and in- 
cluding the period of ripening. Clover is an apparent 
exception, but is probably not really so because after 
the heads begin to die there is an actual loss of dry mat- 
ter from the shedding of the leaves. 

309. Value of crops not proportional to yield. — It does 
not follow when a plant increases in its yield of dry matter 
that its nutritive value has proportionately increased. 
The end to be sought is the largest possible quantity of 
available food compounds, and it is entirely possible 
that changes in texture and in the composition of the 
dry substance may partially or fully offset the greater 
yield. With the meadow grasses this undoubtedly hap- 
pens. The dry matter of mature grass contains a larger 
proportion of fiber than the immature. The progressive 



CATTLE FOODS— NATURAL PRODUCTS ' 



225 



increase of fiber as the plant approaches ripeness is well 
illustrated by analyses made at the Connecticut Experi- 
ment Station of a sample of timothy grass cut at diflPerent 
periods of growth: 



Table XLV. Composition of Dry Substance 


(Per 


Cent) 


Stage of growth of timothy 


Ash 


Protein 


Crude 
fiber 


Nitro- 
gen-free 
extract 


Fats 


Well headed out 

In full blossom 

When out of blossom .... 
Nearly ripe 


4.7 
4.3 
4.1 
3.6 


9.6 
7.1 
7.1 
6.8 


33. 
33.3 
33.8 
35.4 


50.8 
53.3 
53.3 
52.2 


1.9 
2. 
1.7 
2. 



These analyses show that the changes are not con- 
fined to an increase of fiber. The relative proportions of 
ash and protein grow less as the plant matures. An 
examination of the nitrogen-free extract would prob- 
ably show an accompanying decrease of the soluble 
carbohydrates. 

The combined effect of these changes is to cause the 
plant to harden in texture and become less palatable and 
more difficult of mastication. 

310. Age decreases digestibility. — ^The digestibil- 
ity is naturally affected by age. Three American diges- 
tion experiments with timothy hay cut in bloom or 
before show an average digestibihty of the organic mat- 
ter of 61.5 per cent, the average from four experiments 
with timothy cut when past bloom being 55.4 per cent. 
Doubtless the increase in dry matter when timothy 
stands beyond the period of full bloom no more than 
compensates for the decrease in digestibility. Using 
the average coefficients of digestibility and the average 
yields, as given in this connection, the yield of digestible 
o 



226 



THE FEEDING OF ANIMALS 



organic matter would be in full bloom, 2,306 pounds, and 
when out of bloom or nearly ripe, 2,350 pounds. If one 
considers the decrease in palatableness the advantage is 
with the earlier cut hay. 

These facts do not pertain to timothy alone. Other 
meadow grasses are similar in their characteristics of 
growth. The clovers, and especially alfalfa, deteriorate 
to a marked degree from the same cause when allowed 
to ripen too fully before cutting. 

It is probable, all factors considered, that if the grasses 
and clovers which are cut for hay could be harvested when 
in full bloom a desirable compromise would be effected 
between quantity and quality. Alfalfa should be cut no 
later than when the first bloom makes its appearance. 

311. Maize unlike other grasses. — Conditions are 
quite different with maize. This plant in maturing 
gains not only in quantity but in quality. In support of 
this statement data are cited from an experiment con- 
ducted at the Maine Experiment Station. 

The following is the composition of the dry matter 
of the corn when cut at several periods of growth : 



Table XLVI. In 100 Parts Water-free Substance of Maize 















Total 




Stage of growth 


Ash 


Protein 


Crude 
fiber 


Sugar 


Starch 


nitro- 
gen-free 
extract 


Fat 


Very immature, Aug. 15 . 


9.3 


15. 


26.5 


11.7 




46.6 


2.6 


A few roasting-ears, Aug. 28 


6.5 


11.7 


23.3 


20.4 


2.1 


55.6 


2.9 


All roasting-stage, Sept. 4 


6.2 


11.4 


19.7 


20.6 


4.9 


59.7 


3. 


Some ears glazing, Sept. 12 


5.6 


9.6 


19.3 


21.1 


5.3 


62.5 


3. 


All ears glazed, Sept. 21 . 


5.9 


9.2 


18.6 


16.5 


15.4 


63.3 


3. 



Here we see the same decrease in the proportions of 
ash and protein as occurs with timothy, but, unlike 



CATTLE FOODS— NATURAL PRODUCTS 



227 



timothy, the maturing of the maize causes a decrease in 
the percentage of fiber and a material increase in the 
relative amount of the soluble carbohydrates, sugar, 
and starch. 

These data give us every right to expect that the 
dry matter of the mature corn plant is more digestible 
than that of the immature plant, and experimental 
tests show this to be the case. There follows a summary 
of American digestion experiments bearing on this point: 



Table XL VII. Digested from 100 Parts Organic Matter 



Corn fodder 



Max. 



Min. 



Av. 



Corn silage 



Max. 



Min. 



Av. 



Cut before glazing, 13 experiments 
Cut after glazing, 10 experiments . 



71.4 
74.2 



53.6 
61.2 



65.7 
70.7 



77.8 
80.2 



56.6 
65.2 



67.4 
73.6 



The advantage is seen to be with the mature corn. 
It is fair to conclude from all these observations that 
harvesting the corn plant when immature is injudicious 
from every point of view. 

312. Alfalfa. — Alfalfa has become in many parts of 
the United States one of our most important forage crops. 
Its points of excellence are a high degree of palatableness, 
large relative yield, its partial independence, at least, 
of a soil-supply of nitrogen, and its efficiency as a soil- 
renovating crop. From three to ^ve cuttings may be 
made annually; and the yield, according to records in 
central New York, sometimes reaches the equivalent of 
five tons of hay. The fact that it is a leguminous plant 
indicates a useful place in farm cropping because of the 
fact that the percentage of protein it contains is consider- 
ably higher than that of the true grasses. 



228 THE FEEDING OF ANIMALS 

In order to successfully establish this plant in many 
sections it is necessary to inoculate the soil with the bac- 
terium that sustains a symbiotic relation with this 
legume, and coapply some form of lime when the soil 
has a high degree of acidity. 

It should be stated that the relative feeding value of 
alfalfa has been overestimated as compared with other 
legumes, such as the clovers. It is doubtful whether 
alfalfa hay cut and cured under the best of conditions is 
superior in quality to the best quality of clover hay. 

SILAGE 

About forty years ago a new process for preserv- 
ing crops in a green condition was introduced into the 
United States, viz., ensilage. This consists in storing 
green material in receptacles called silos, in masses 
sufficiently large to insure certain essential conditions. 
Within a brief period after maize or other green material 
is packed in a silo the mass becomes perceptibly warm, 
and in the course of two or three days it reaches its maxi- 
mum temperature, which is much above the average heat 
outside. This rise in temperature is due to chemical 
changes which involve the consumption of more or less 
oxygen and the production of compounds not previously 
existing in the fresh material. 

313. Nature of the changes in the silo. — ^These changes 
are very complex. They have been regarded as due to 
the activity of a variety of ferments, principally those 
which are believed to cause the formation of alcohol 
and acetic, lactic, and other acids. Whether the oxida- 
tions occurring in the silo are wholly induced by ferment 
action or in part at least are the result of oxidations 



CATTLE FOODS— NATURAL PRODUCTS ' 229 

brought about in other ways is a point over which there 
has been some recent interesting discussion. 

Babcock and Russell carried on at the University 
of Wisconsin able and very suggestive investigations 
concerning the causes of silage formation. They con- 
clude that the theory that silo changes under normal 
conditions are due wholly to bacteria "does not rest on a 
sound experimental basis." 

Their data led them to regard respiratory processes, 
both direct by the plant cells and intramolecular, as 
the main causes of the chemical transformations which 
produce carbon dioxid and the evolution of heat within 
the ensiled mass. The direct respiration appropriates the 
oxygen confined in the air spaces of the silo, and the 
intramolecular respiration uses oxygen combined in the 
tissues. Both forms of respiration go on only so long 
as the plant cells remain alive. Concerning bacteria 
the authors say: "The bacteria, instead of function- 
ing as the essential cause of the changes produced in good 
silage, are on the contrary only deleterious. It is only 
where putrefactive changes occur that their influence 
becomes marked." 

Doubtless intramolecular respiration is continued 
longer in immature and succulent plant tissues than in 
tissues where the cells have reached maturity, and so the 
losses in the silo with immature plant substance are 
greater than with mature. Analyses of silage from 
frozen corn and feeding trials with this material show 
that it is not economy to cut immature corn for fear of 
frost, as the increase of dry matter much more than bal- 
ances the loss from the freezing. 

314. Losses in silo. — Whatever are the inducing 
causes, a careful record of what takes place in the silo. 



230 " THE FEEDING OF ANIMALS 

shows that the silage contains considerably less dry 
substance than the original fresh material. Loss occurs 
through the formation of volatile products. An examina- 
tion of the fresh corn and of the silage shows that the 
latter contains much less sugar than the former, some- 
times none at all. In the place of the sugar we find a 
variety of acids, chiefly acetic and lactic. This is a change 
similar to the formation of acetic acid in cider and lactic 
acid in milk, in all cases sugars being the basal com- 
pounds. Determinations of acidity in silage by Morse 
during several years showed it to vary from .8 to 1 per 
cent. Along with the development of these acids, carbon 
dioxid and water are formed from the carbon compounds 
of the ensiled material. In other words, combustion takes 
place and more or less of dry matter is actually burned 
up, thus generating heat and causing rise of temperature 
of the fermenting mass. The amount of dry matter 
thus lost is determined partly by the kind of crops and 
the care with which the silo is built and filled. 

Another important chemical change induced by fer- 
mentation is a splitting up of a certain portion of the 
proteins of the fermenting material into amino acids, 
some of which compounds may have a more limited nutri- 
tive function than the proteins. Investigation conducted 
at the Pennsylvania State College showed that in some 
cases over half the nitrogen of silage existed in the amino 
acid or amide form, this being between two and three 
times as much as was found in the original fodder. Proba- 
bly the same change takes place in the field-curing of 
fodder, but no data are available on this point. Starch 
seems to resist the usual silo oxidations. In certain experi- 
ments a considerable loss of nitrogen is reported. It is 
hard to understand, though, how this can occur to any 



CATTLE FOODS— NATURAL PRODUCTS - 231 

large extent unless the conditions in the silo are very 
bad, so that putrefactive fermentations set in. An exten- 
sive loss of nitrogen compounds certainly would indicate 
very serious and long-continued destructive changes. 

Steaming the corn seems to depress the fermenta- 
tions and decrease the percentage of acids that form. 
Knisely found .3 to .88 per cent acidity in steamed silage 
and 1 to 1.6 per cent in unsteamed. 

315. Com an important silo crop. — ^The nature of 
the changes and losses in producing silage have been 
dwelt upon partly because corn, the principal silo crop, 
is one of our most important forage crops, perhaps the 
most so on a dairy farm, and partly in order to illustrate 
the necessity and value of good management in preserv- 
ing this crop by the silo method. Moreover, the loss that 
is incident to the field-curing of maize is practically the 
same in kind and is fully as large as that pertaining to 
silage, so that the facts presented are pertinent to both 
methods as well as to all circumstances where similar 
oxidations and fermentations are likely to ensue. 

316. Extent of loss in the silo. — ^The extent of the loss 
of dry substance is important. It measiu^es in a general 
way the difference between the food value of the silage 
and of the fresh material. The silo combustion reduced 
the energy or heat value which the fermented fodder 
will have whenever it is eaten by the animal. The 
heat lost would supply energy to an animal were the 
combustion to occur within the animal instead of in the 
silo. It is desirable, therefore, to know the extent to 
which dry substance is actually broken up in the prepara- 
tion of silage. This loss has been measured by several 
investigators, and, as was to be expected, it has been 
foimd to depend greatly upon the conditions involved, 



232 



THE FEEDING OF ANIMALS 



the figures reached varying from about 2 to nearly 40 
per cent of the dry matter of the fresh crop. In a majority 
of cases the loss has been over 15 and less than 20 per 
cent. King, of the Wisconsin Experiment Station, who 
gave the production of silage much study, concluded 
upon the basis of his observations that in good practice 
the necessary reduction of dry matter in making corn 
silage need not exceed 4 to 8 per cent, and with clover 
silage from 10 to 18 per cent. 

317. Necessary loss in silo. — ^The necessary loss is 
explained as being that which occurs in the interior of 
the mass where all outside air is excluded and other 
favorable conditions prevail. Considering the contents 
of the silo as a whole, it will require careful attention to 
all details in order to reach King's estimate with the best 
conditions attainable. 

This investigator found that 64.7 tons of silage packed 
in a silo lined with galvanized iron, thus securing a per- 
fect exclusion of air, lost an average of 6.38 per cent of 
dry matter. This silo was filled in eight detached layers, 
and the proportion of loss in these several divisions, as 
affected by location, is most suggestive : 

Table XLVIII 



Silage 



Dry matter 
lost 



Surface layer 
Seventh layer 
Sixth layer . 
Fifth layer 
Fourth layer , 
Third layer . 
Second layer . 
Bottom layer 



Pounds 

8,934 
8,722 
14,661 
48,801 
13,347 
7,723 
12,689 
12,619 



Per cent 

32.53 
23.38 
10.25 
2.10 
7.01 
2.75 
3.53 
9.47 



CATTLE FOODS— NATURAL PRODUCTS ' 233 

The mean loss of dry matter in the lower six layers 
was only 3.66 per cent. These figm-es show that it is 
proJBtable to make the walls of the silo air-tight, even 
at large expense. 

318. Financial importance of silo losses. — ^The im- 
portance of reducing the loss in the silo to the lowest 
possible percentage is almost self-evident. As this point 
is capable of mathematical demonstration, it will be 
interesting and suggestive to calculate what might take 
place in a hundred-ton silo. In many of the trials which 
appear to have been conducted under not unusual con- 
ditions, a loss as high as 20 per cent of the dry matter 
put in the silo has been observed. In a hundred-ton silo 
filled with corn containing 25 per cent of dry matter, or 
50,000 pounds, this would amount to the destruction of 
10,000 pounds of dry food substance. As the loss falls 
chiefly on the sugars or other soluble bodies which are 
wholly digestible, the available nutrients in the fresh 
material are diminished by an amount of digestible dry 
matter equivalent to what would be required by ten 
milch cows during two months. If, therefore, by good 
planning and extra care this waste could be reduced three- 
fourths or even one-half, the food resources for carrying 
a herd of cows through the winter would be materially 
increased, from five to seven and one-half tons of timothy 
hay being the measure of the saving in a hundred-ton 
silo. 

319. Ensiling vs. field-curing. — ^The question is often 
raised whether ensilage or field-curing is the more waste- 
ful method of preserving a forage crop. Considerable 
study has been given this matter, and the results secured 
have been taken as a justification of the statement that 
one method is about as economical as the other, which 



234 THE FEEDING OF ANIMALS 

is correct if we consider only the outcome of certain com- 
parisons. A general survey of the data accumulated 
shows that on the whole the waste has been the larger 
in field-curing. Observations made in six states reveal 
a loss by the old method as low as 18 per cent in only 
one case, and from 21 to 34 per cent in all others. Pos- 
sibly under favorable conditions of weather, field-cured 
corn fodder may lose as little dry matter as silage, though 
this is doubtful, but in bad weather the waste from the 
exposed fodder is extensive. The greatest advantage in 
silo preservation is that conditions can usually be con- 
trolled with more satisfactory average results than are 
possible in field-curing. Other advantages pertain to the 
silo which are of a business nature and which need not 
be discussed here further than to aflfirm that the cost of 
a unit of food value is in general diminished by the use 
of the silo. 

320. Crops for silage. — The number of crops that may 
be successfully ensiled is not large. Maize is the most 
valuable one for this purpose, and clover and alfalfa 
are stored in this manner with a fair degree of success 
although silage from these latter crops often, if not gen- 
erally, carries an offensive odor. So are peas, especially 
when mixed with corn. The true grasses and cereal 
grains outside of corn are not desirable silo crops, first 
because the silage from them is generally poor in quality, 
and second because usually they may be successfully and 
more cheaply stored in an air-dry condition. Any crop 
with a hollow stalk, giving an inclosed air space — oats, 
for instance — is not adapted to silo conditions, and there 
is no justification for ensiling any fodder which is sus- 
ceptible of prompt and thorough drying in the field, 
because in such cases there is an unnecessary waste of 



CATTLE FOODS— NATURAL PRODUCTS ' 235 

food substance by fermentation and an unnecessary 
handling of many tons of water contained in the green 
material, with no compensating advantages. But any 
crop used for the production of silage should be managed 
in the most eflBcient manner. A few general facts may 
be discussed in this connection. 

321. Construction of silos. — Silos that are of proper 
construction and shape have air-tight perpendicular 
walls and a height considerably in excess of either of 
the horizontal dimensions. These conditions are essen- 
tial to the completest possible exclusion of air and to 
the closest possible packing of the material, with a mini- 
mum of exposed upper surface. 

Silos may be either round, square, or rectangular, 
provided that in the latter case one horizontal dimen- 
sion is not too greatly in excess of the other. The shape 
of a silo which is most economical and efficient is not the 
same for all conditions, although the round and square 
forms hold most in proportion to the wall area. Many 
farmers desire to have the silo in the barn, and generally 
there the square or rectangular form is more economical 
of space than a round one. When built outside the barn, 
the round form, according to the opinion of many, may 
be used to advantage both as to expense and results. If 
a square or rectangular silo is built the corners should 
be cut off inside in order to prevent an access of air and 
the decay which occurs at those points when this is not 
done. Several kinds of materials have been used suc- 
cesfully in building silos, wood, brick, and stone. If the 
walls are of masonry the inner surface must be cemented 
not only air-tight but so smoothly as to allow easy and 
uniform settling of the silage without leaving air spaces. 
If wood is used, which is the more common material, the 



236 THE FEEDING OF ANIMALS 

inside construction must meet the same requirements. 
Lining a wooden silo with iron has been suggested as 
practical and economical. Cement is used successfully 
in the same way. Economy demands that as a preventive 
against decay the inner woodwork should at least be 
treated with some preservative, which may also serve the 
purpose of obviating excessive swelling and shrinking of 
the lining boards. 

322. Filling the silo. — ^The condition of the crop and 
the manner of filling a silo determine to a great extent the 
character of the silage. Obviously it should be so done 
as to reduce the loss of food compounds to the lowest 
possible point. Three points are prominently discussed 
in this connection: (1) the condition of the crops, (2) the 
preparation of the material, and (3) the rate of filling. 

323. Mature com desirable for silage. — Experience 
has thoroughly demonstrated that the maturity of a 
crop influences its value for silage. This is known to be 
especially true of the corn crop. An immature corn 
fodder, which always carries a high percentage of water 
with less of the matured products, such as starch, is 
always certain to change to very acid silage. On the 
contrary, mature corn, when properly handled, is con- 
verted into a product with the minimum acidity and with 
an appearance and aroma much superior to that from the 
immature plant. Neither are satisfactory results secured 
from material that is overdry. It may be stated in gen- 
eral terms that the best results are obtained when the 
proportion of dry matter falls between 25 and 30 per 
cent. If corn is harvested for the silo after the kernels 
have begun to glaze, while the leaves are still green and 
before they show dryness, other conditions being favora- 
ble, it will meet every requirement for good silage. 



CATTLE FOODS— NATURAL PRODUCTS ' 237 

324. Cutting and shredding ensilage material. — 
Whether the material with which a silo is filled shall be 
put in whole or after cutting or shredding depends to 
quite an extent upon its degree of coarseness. It is prob- 
able that clover, and even the smaller varieties of maize, 
are often successfully preserved without cutting, but no 
one professes that this can be done with the coarser 
varieties of maize. It is generally admitted that, with 
maize, cutting or shredding it increases the probability 
of satisfactory preservation, because the finer mechanical 
condition allows more uniform packing and prompter 
and more uniform settling. The highest grade of silage 
with the minimum loss is undoubtedly more surely made 
from cut or shredded material. 

325. Rate of filling silo. — In the early days of silos it 
was taught that to insure the least possible waste by 
fermentation, the silo should be filled with the maximum 
rapidity and then promptly weighted. Following this 
view was the conclusion on the part of some that very slow 
filling with no packing other than that given by the weight 
of the mass, was the proper way to make silage of the 
highest quality. This method was advocated for produ- 
cing sweet (?) silage. It allowed violent fermentation at 
first with resulting high temperatures, by which means 
bacteria were supposed to be killed and subsequent 
fermentations prevented, a conclusion so far not sus- 
tained by scientific observations. Moderately slow and 
continuous filling, rather than very rapid, has been 
advocated by leading authorities. Two advantages were 
claimed for this method, one being that more material 
can be stored in the silo and the other is that silage of a 
higher quality is produced with a smaller loss of dry 
matter. The first point must be conceded and the second 



238 THE FEEDING OF ANIMALS 

claim may be true, although in part it lacks proof. It is 
hard to understand why slow filling, especially if inter- 
mittent, should not increase rather than decrease the 
losses of food compounds. Certainly the less compact the 
mass the more intense the oxidation and the higher the 
temperature, the latter condition indicating with cer- 
tainty the extent of the combustion. This point is illus- 
trated by results reached at the Pennsylvania State 
College when the chemical changes in two large tubs of 
sorghum silage were studied, one of which was com- 
pactly filled and weighted at once and the other loosely 
filled and weighted after five days. The temperature 
rose 17° higher in the latter than in the former, with a 
loss of two and one-half times as much organic matter 
from the loosely filled tub. It follows from the theory of 
Babcock and Russell, previously noted, that the less the 
oxygen available in the air spaces and the quicker the 
plant tissue dies the less will be the combustion or loss 
of organic matter. These authors suggest as a prac- 
tical application of their theory that the air be excluded 
from the silo as rapidly as possible and only mature corn 
be ensiled, because such tissue will die sooner than im- 
mature, having less vitality. Their data seem to prove 
conclusively, also, that the evolution of much heat when 
a fodder is first ensiled is not essential to the formation 
of first-class silage. The repeated exposure of a loose 
upper stratum, which occurs with slow, intermittent 
filling, must cause extensive loss from portions of the silo. 
It must be held, in view of the experimental data now at 
hand, that the more promptly the air is excluded and 
expelled by the reduction of the contents of the silo to a 
condition of maximum compactness, the less will be 
the fermentation losses. The term "sweet silage'* me ms 



CATTLE FOODS— NATURAL PRODUCTS - 239 

but little as indicating completeness of preservation, for 
it may even be the result of extensive fermentations, a 
condition expensively secured. Its significance is entirely 
different when the sweetness is due to proper maturity 
of the fodder plant. 

THE STRAWS 

326. When the grain plants which produce seeds 
valuable for cattle and human foods are threshed, or 
in some way manipulated to remove the seeds, the other 
parts of the plant constitute what we call straw m the 
case of the cereal grains and legumes, and stover in 
the case of maize. These fodders differ from the same 
plants, when cut in a less mature condition for hay or 
fodder, in being more tenacious and less palatable, with 
a smaller proportion of the more digestible, and there- 
fore more valuable, compounds. The most useful of these 
materials for feeding purposes are corn stover, oat straw, 
and the legume straws. These are better relished by farm 
animals than wheat and barley straws, which are utilized 
mostly for litter. 

ROOTS AND TUBERS 

327. Certain species of plants, more especially beets, 
mangel-wurzels, turnips, rutabagas, carrots, and pota- 
toes, are agriculturally valuable because of the store of 
nutrients which they deposit in subterranean branches 
or in roots. The original purpose of this deposit is, in 
the case of potatoes and artichokes, to nourish the young 
plants of the next generation, or, in the case of bien- 
nials like beets, to supply the materials for the seed- 
stalk and seeds of the second year. Potatoes are not 
grown primarily as food for cattle, but roots have for 



240 THE FEEDING OF ANIMALS 

many years been a standard crop for feeding purposes. 
This class of crops has the advantage of furnishing very 
palatable, succulent food, which may be kept in per- 
fect condition during the entire winter season, an advan- 
tage which is not wholly measured by the actual quan- 
tity of nutrients supplied by these materials. 

The disadvantages of these crops are that they are 
somewhat expensive to grow and necessitate the hand- 
ling of large weights of water. A ton of turnips or man- 
gels may furnish even less than 200 pounds of dry sub- 
stance, to secure which 1,800 pounds of water must be 
lifted several times. The percentage of dry matter in 
roots and tubers varies in American products, on the 
average, from 9.1 per cent in mangel-wurzels and tur- 
nips to 28.9 per cent in sweet potatoes. Potatoes are 
more nutritive pound for pound than roots. The dry 
matter of this class of cattle foods is principally carbo- 
hydrate in its character, though the proportion of pro- 
tein is as large and in some cases larger than in certain 
grain foods. 

Two conditions are essential to the winter storage of 
roots without deterioration, viz., a low temperature, 
as near freezing as possible, and abundant ventilation. 
Large masses of roots un ventilated are apt to "heat," 
and sometimes decay, with a resulting large loss in nutri- 
tive value. 

GRAINS AND SEEDS 

328. The conditions which provide for the mainte- 
nance of plant life also subserve the interests of the animal 
kingdom. We have seen that this is true of the store 
of starch and other compounds in tubers and roots, 
and it is a fact of much larger significance in the produc- 



CATTLE FOODS— NATURAL PRODUCTS 241 

tion of seeds, especially those of our cereal grains, includ- 
ing barley, maize, oats, rice, rye, and wheat. Other 
seeds, such as buckwheat, cottonseed, flaxseed, beans, 
and peas, also contribute an important addition to our 
animal feeding-stuffs. In all these species there is de- 
posited in the seed coats and either around the chit or 
embryo or in the seed leaves of the embryo, a store of 
protein, starch, and oil, the purpose of which is to supply 
materials for gro^i:h during germination. This deposit 
of plant compounds represents the highest t^^e of vege- 
table food, whether we consider concentration, palatable- 
ness, or nutritive efficiency. Besides, it is in such form 
that with ordinary precautions it is capable of indefinite 
preservation, without loss. 

329. Storage of grain. — It often occurs that when 
newly-harvested grain is stored in bulk it heats and 
grows "musty.'* This condition is due to fermentations 
that are made possible by the high water-content of the 
fresh grain and which involve a loss of dry substance. It 
is very desirable that grain shall be thoroughly dried 
before threshing, and it is generally desirable to secure 
additional drying after threshing before storing it in 
large bins. 

The agricultural value of the cereal grains is much 
enhanced by their adaptability to a great range of soil 
and climatic conditions. They are the American farmer's 
great reliance for the production of the highest class of 
cattle foods. Maize, especially, is grown from Maine to 
Florida and from the Atlantic to the Pacific. These 
crops are useful, not only for their seeds but as fodder 
plants. For soiling purposes, as well as a source of dried 
forage they are highly important. 



CHAPTER XIV 

CATTLE FOODS— COMMERCIAL FEEDING- 
STUFFS 

The cereal grains and other seeds are the source of 
a great variety of by-product feeding-stuffs which have 
a large and widespread use, especially in the dairy sec- 
tions of the United States. In the preparation of a 
great variety of human foods and of other materials 
important in industrial life, certain by-products are 
obtained which represent particular parts or compounds 
of the grain or seed. Whenever the methods of manu- 
facture are such as not to injure the palatablen^ss or 
healthfulness of these waste products, they may be 
utilized as cattle foods. As a matter of fact, a large 
proportion of our commercial feeding-stuffs is of this 
general kind and because these materials differ greatly 
in composition and nutritive value, the purchaser should 
clearly understand their source and character. Changes 
in methods and new manufacturing enterprises are 
constantly modifying the composition of old products 
and introducing new ones, consequently the facts as 
they exist at one time may not be applicable for a long 
period. There is need therefore of constantly keeping 
informed in regard to the various cattle foods found in 
the markets, if they are to be economically purchased 
and wisely used. 

330. Classes of commercial by-product feeding- 
stuffs. — For the purposes of description, the various 

(242) ^ 



COMMERCIAL FEEDING-STUFFS ' 243 

by-product feeding-stuffs may be classified according 
to their origin. Their sources are mainly as follows: 

1. The milling of wheat and other grains. 

2. The manufacture of oatmeal and a variety of 

breakfast foods. 

3. The manufacture of beer and other alcoholic drinks. 

4. The manufacture of starch and sugars, chiefly 

from corn. 

5. The manufacture of beet-sugar. 

6. The extraction of oils, chiefly linseed oil and cotton- 

seed oil. 

7. Screenings from the milling of wheat, and other 

refuses. 

8. Compounded feeds made up from a variety of 

by-products. 

331. Wheat offals. — No commercial feeding-stuffs are 
regarded with greater favor, or are more widely and 
largely purchased by American feeders than the by- 
products from milling wheat. Wheat bran and mid- 
idlings are cattle foods of standard excellence, whether 
we consider composition, palatableness, or their relation 
to the quality of dairy products. These feeding-stuffs 
consist of particular parts of the wheat kernel, a knowl- 
edge of the structure of which aids greatly in under- 
standing what they are and why they possess certain 
chemical and physical properties. 

332. Structure of the wheat grain. — ^To ordinary 
observation the wheat grain appears to be merely a 
seed, but it is really a seed contained in a tightly-fitting 
seed pod. This pod, which is woody and tough, con- 
stitutes the outer coating of the kernel. On the seed 
itself are two more hard and resisting coatings, one of 
which is double, that serve to protect the softer parts. 



244 THE FEEDING OF ANIMALS 

We find, then, that in every wheat kernel there are three 
coats entirely unlike the rest of the grain, because they 
consist of hard, thick-walled cells containing but little 
starch, if any, with a much larger proportion of cellulose 
or fiber than is found in the inner portion of the kernel 
(Figs. 11 and 12.) 

Just inside the innermost of the three outer coats 
is a layer of material very rich in protein compounds, 




Fig, 11. Section of entire wheat kernel (enlarged 16 diameters). 1, seed 
pod and seed coatings; 4^ gluten layer; 5, mass of starch cells. 

which may properly be called the gluten layer. The 
great bulk of the wheat kernel is made up of cells closely 
filled with starch grains/ This is the soft white por- 
tion of the seed and is that which furnishes the flour. All 
of these parts serve to protect, and, in germination, to 
nourish the essential portion of the seed, the germ or 
embryo which lies "at the lower end of the rounded back 
of the kernel." Bessey, in an admirable description of 



COMMERCIAL FEEDING-STUFFS 



245 



the wheat kernel, tells us that the percentage propor- 
tions of its various parts are as follows : 



Per cent 

Coatings 5 

Gluten layer 3-4 



Starch cells 
Germ . . 



Per cent 

84-86 

6 



333. The milling of wheat. — We are now prepared to 
understand the significance of the statement that in mill- 
ing wheat the flour of various grades comes from the 
starch cells, the other 
portions passing into 
the bran, shorts, and 
middlings, which col- 
lectively are termed the 
offal. If only the coat- 
ings, gluten layer, and 
germ went to make up 
the offal it would in- 
clude only about 14 or 
15 per cent of the 
kernel, the flours taking 
the remainder, but, as 
a matter of fact, no 
milling methods so far 
used completely separate the starch cells from the 
inclosing tissue, so that the offal is perhaps never less 
than 25 per cent of the whole grain. In milling tests con- 
ducted by the Minnesota Experiment Station, the offal 
from several lots of wheat, good and bad, varied from 
25 to 40 per cent. If four bushels of w^heat are consumed 
per capita by the population of the United States, which 
is below the estimate, and if only one-quarter of this is 
converted into offals, the amount of bran and middlings 
annually consumed by our domestic animals is not less 




Fig. 12. Partial scetion of wheat kernel 
(enlarged 155 diameters). 1, seed pod; 
2, outer seed coat; S, inner seed coat; 
4, gluten cells; 6, starch cells. 



246 



THE FEEDING OF ANIMALS 



than 3,000,000 tons, barring the quantity which may be 
exported. 

334. Composition of milling products of wheat. — It 
is a fact worthy of special comment that because of 
a somewhat irrational standard of excellence for bread, 
certain parts of the wheat kernel best adapted to the 
nourishment of young and growing animals are separated 
with great care to be used by the brute life of the farm 
rather than by the farmer and his family. A comparison 
of the composition of the whole wheat kernel, white 
flour, and the various parts of the offal emphasizes this 
point. The figures given are taken from the results of 
an investigation by Snyder, of Minnesota, in which he 
compared the composition of different grades of wheat 
with that of the flour and products obtained from them: 



Table XLIX. Composition of Wheat and Its 

Products (Per Cent) 


MiLLIN 


G 




Water 


Ash 


Protein 


Fiber 


Nitrogen- 
free 
extract 


Starch 

and 
dextrine 


Fat 




Total 


Gluten 




Wheat kernel . 
Wheat flour 
Wheat germ . 
Wheat shorts . 
Wheat bran 


10.2 
10.6 
10.4 
10.1 
10.4 


1.8 
.4 
2.7 
3.1 
5.9 


13.7 
11.2 
15.7 
13.1 
15.4 


13.5 
11. 
15.3 
12.9 

14.8 


3.2 

*5.'4 
10.2 


69. 

77.3 

67.7 

65.3 

52.9 


64.9 
70.4 


2. 

.5 
3.5 

2.9 
5. 



The greater richness of the coatings of the kernel 
in mineral matter, protein, fiber, and oil is made plain 
by this comparison. There is four times as large a per- 
centage of mineral matter and of oil in the whole wheat 
as in the flour, nearly one-third more protein and con- 
siderably less starch. On the other hand, the bran is not 
less than ten times richer in mineral compounds and oil 



COMMERCIAL FEEDING-STUFFS 247 

than the flour, one-third richer in protein, with corres- 
pondingly less starch. "Graham" flour, which contains 
more or less of those parts which pass into the offal in 
milling white flour, does not differ so much from the 
whole kernel. Middlings differ from bran in containing 
less of the hard, tough coatings and more of the finer 
parts of the kernels, and this feeding-stuff varies from 
the coarser kinds to the fancy middlings, according to 
the proportion of starchy material present. Red Dog 
flour is counted among the offals from milling wheat, and 
it represents the dividing line between the middlings and 
the high-grade flour. 

335. Milling processes compared. — ^There is a belief 
more or less prevalent that bran from the old milling 
processes which contained more of the starchy part of 
the kernel than is now the case, was more valuable than 
roller process bran is. It is probable that a greater pro- 
portion of starch increases the digestibility of bran, and 
in this sense the old process bran was superior to the 
roller process product; but, on the other hand, the latter 
is more nitrogenous than the former and is therefore 
more efficient as a protein supplement to home-raised 
foods. 

336. Screenings. — ^Wheat, when sold to the mills, con- 
tains besides inferior wheat grains a certain percentage 
of foreign materials such as other grains, weed seeds, 
chaff, bits of straw, and even particles of grit. Before the 
wheat is milled these materials are removed and in com- 
merce are known as screenings. While the percentage 
of this foreign matter in wheat is small, the aggregate 
quantity of this offal put on the market is very large. 
Screenings contain ingredients of greatly varying qual- 
ity, some of which are very inferior. This offal is almost 



248 



THE FEEDING OF ANIMALS 



wholly used as a part of the so-called compounded 
feeds, a fact to be reckoned with by purchasers of these 
mixtures. 

Recently millers are mixing these screenings with the 
bran. Unquestionably the bran thus suffers deteriora- 
tion proportionate to the quantity and quality of the 
screenings. The guarantee accompanying such mix- 
tures generally specifies "wheat bran with the mill run 

of screenings." This is 
a part of the growing 
practice to foist upon 
the consumer a great 
variety of by-products 
and refuses, some good 
and some bad. 

337. Residues from 
breakfast foods. — In 
the manufacture of 
breakfast foods, the 
use of which has be- 
come so prevalent, cer- 
tain by-products are 
obtained which are now^ found in the market as cattle 
foods. The preparation of oatmeal and similar materials 
involves the selection of the finest oat grains, i. e., those 
having the largest kernels, from which the hulls are 
removed. These hulls and the smaller oat grains, and 
perhaps bran, constitute by-products which, after being 
finely ground, are sold as oat-feed and in various mix- 
tures. As the sale of oat hulls as such, or in a fraudulent 
way when mixed with other substances, is likely to occa- 
sion a financial loss to feeders, it is desirable to clearly 
understand the situation. We shall accomplish this by a 




Fig. 13. Section of entire oat grain 
(enlarged 16 diameters). 0, hull; 1, seed 
coat; j^, gluten layer; 6, mass of starch 
cells. 



COMMERCIAL FEEDING-STUFFS 



249 







:.:?i>r^ 






study of the relation of the oat hulls to the kernel in 
quantity and composition. (Figs. 13 and 14.) 

338. The oat grain, oat hulls. — It is common knowl- 
edge that the oat grain consists of a hull and kernel, 
which are easily separated. The former is fibrous and 

tough, and the latter .. ._ 

soft with very little fiber. 
The hull forms a con- 
siderable portion of the 
grain. In 1894, the Ohio 
Experiment Station 
made a study of numer- 
ous varieties of oats. It 
was found that with 
sixty-nine varieties the 
hulls constituted from 
24.6 to 35.2 per cent of 
the whole grain, the aver- 
age being 30 per cent. 
It did not appear, con- 
trary to the general 
opinion, that the pro- 
portion of hull was larger 
with light oats than with 
heavy, although observa- 
tions elsewhere have sustained the popular view. At the 
Mustiala Agricultural College twenty-eight samples of 
Finnish oats and twenty samples from five other coun- 
tries gave from 28 to 32 per cent of hulls. Wiley states 
that the average proportion of hull to kernel is as three 
to seven, which varies with locality. The figures in the 
next table show the composition of the dry matter of 
whole oats, oat hulls, and the hulled kernel : 




Fig. 14. Partial section of oat grain 
(enlarged 170 diameters). 0, hull; 1, 
seed coat; 4, gluten cells; 5, starch 
cells. 



250 



THE FEEDING OF ANIMALS 



Table L 



Whole oats, 30 samples . . 
Hulls, New Jersey .... 

Hulls, Vermont 

Hulls, Wisconsin .... 
Hulled kernels, 179 analyses 



Ash 



Per cent 

3.4 

7.2 
6.9 
7.8 
2.3 



Protein 



Per cent 

13.2 
3.5 
4.4 
2.3 

15.4 



Fiber 



Per cent 

10.8 
32. 
29.5 
50.1 
1.5 



Nitrogen- 
free 
extract 



Per cent 

67. 

56.3 

57.2 

39. 

72.1 



Fat 



Per cent 

5.6 

1. 

2. 

.8 
8.7 



The inferiority of the hulls as compared with the whole 
grain or with the hulled kernels is very apparent, because 
of their smaller proportion of protein and oil and their 
much larger percentage of fiber. If hulls are purchased 
at all the price should be on a par with that at which the 
coarsest and cheapest grades of fodders are sold. 

339. Oat clippings. — Oat clippings is an offal intro- 
duced into the market at a later date than oat 
hulls. This waste consists of the hairs, oat dust, 
and light oats mostly separated from the oat kernel by 
the clipping process. Such material is inferior both as 
to composition and digestibility. It is now much used 
in compounded feeds. Farmers will do well to carefully 
inquire into the character of the so-called oat feeds and 
compounded feeds offered to them. These articles are 
often oat hulls, poor oats, and other refuse mixed with 
corn or with by-products of another class and are dis- 
tinctly inferior to the whole grains. Such low-grade 
mixtures are not wisely purchased at prices nearly equal 
to those ruling for whole cereal grains of any kind. 

340. Barley feed. — This is a by-product from the 
manufacture of pearled barley, and like oat feed consists 
of the hulls and portions of the grain and contains more 



COMMERCIAL FEEDING-STUFFS 251 

fiber and less starch than the original grain, its value 
being proportionately less, 

341. Hominy feed. — Hominy is made from corn and 
consists of the hard portions of the kernel, leaving as a 
residue the hull, germ, and part of the starch cells, which 
collectively are sold as hominy feed or chop. This differs 
from the whole kernel but little in composition and is 
practically as digestible. 

342. Brewers' grains; maltsprouts. — Sugar in some 
form is at present essential to the production of alcoholic 
beverages, a cheap supply of which is obtained by con- 
verting the starch of certain cereal grains into maltose, 
which afterward passes into fermentable sugars. This 
result is accomplished by placing barley and other grains 
under such conditions of moisture and temperature that 
they germinate. We have already seen that during ger- 
mination the starch of a seed is converted into maltose 
through the action of a diastatic ferment (see Par. 94), 
and the maltster arrests this germination at a point 
which gives the maximum quantity of sugar. The malted 
grains are subsequently dried and the sprouts after 
removal appear in our markets in an air-dry condition, 
constituting one of our valuable nitrogenous feeding- 
stuffs. The malted grains are then crushed, the sugar is 
extracted from them, and the residue is known in com- 
merce as brewers' grains, a by-product feeding-stuff fairly 
rich in protein. The high proportion of protein is due to 
the fact that the starch has been largely removed, 
leaving the other constituents behind in a more concen- 
trated form. These grains are mostly dried and may 
then be shipped to distant markets in a perfectly sound 
and healthful condition. 



252 



THE FEEDING OF ANIMALS 



343. Residues from starch and glucose manufactiu-e. — 

The gluten meals, gluten feeds, corn bran, and the like 
are residues obtained in the manufacture of starch and 
glucose from the maize kernel. This kernel, like that of 
wheat, is not homogeneous in structure and composition, 
a condition which makes it possible, through mechanical 
or chemical operations, to secure a variety of by-products 
greatly unlike in texture and in their proportions of 
nutrients. 

344. Structure of the maize kernel. — ^All this is made 
plain through a consideration of the structure of the 
maize kernel. This seed is in some respects similar to 
that of wheat. We have first an outside husk or skin 
made up of two distinct layers, one less than we find in 




Fig. 15. Section of entire maize kernel (enlarged 10 diameters). 1, 
outer layer of husk or skin; 2, inner layer of skin; ^, gluten layer; 
6, mass of starch ceUs. 

wheat. This skin is rich in fiber, scarcely any being fouad 
in the other portions of the kernel. Next on the inside 
is a layer of cells rich in gluten. The body of the kernel 
surrounding the germ or embryo consists of closely com- 
pacted starch cells, though some of this interior tissue on 



COMMERCIAL FEEDING-STUFFS 



253 



the sides of the kernel next to the walls is flinty. We 
may properly speak of the maize kernel, then, as consist- 
ing of fom- parts— the husk, the gluten layer, the germ, 
and the starchy and 
hard part. (Figs. 15 
and 16.) At the New 
Jersey Experiment Sta- 
tion one hundred grains 
of the maize kernels 
were separated as nearly 
as possible into the 
skin, germ, and main or 
starchy and hard por- 
tions. These parts were 
analyzed, and below 
is given their compo- 
sition : 




Fig. 16. Partial section of maize 
kernel (enlarged 170 diameters). 1, 
outer layer of skin; 2, inner layer of 
Bkin; 4, gluten cells; 5, starch cells. 



Table LI. Composition of Dry Substance of Maize Kernel 

(Per Cent) 





Ash 


Protein 


Fiber 


Nitrogen- 
free 
extract 


Fat 


Propor- 
tion 
of parts 


Original kernel . . . 

Skin 

Germ 

Starch and hard part. 


1.7 

1.3 

11.1 

.7 


12.6 

6.6 

21.7 

12.2 


2. 

16.4 

2.9 

.6 


79.4 
74.1 
34.7 

85. 


4.3 

1.6 

29.6 

1.5 


100. 
5.5 
10.2 
84.3 



These figm-es are essentially similar to those obtained 
by other investigators, including Salisbm-y, Atwater, 
and Balland. 

345. Manufacture of starch. — ^The separation of starch 
cells (see Par. 102) from other parts of the kernel is 
accomplished mechanically. Either before or after soak- 



254 THE FEEDING OF ANIMALS 

ing in warm water, the maize kernels are crushed into a 
coarse powder. The various parts separate in water by 
gravity, the hulls floating on the surface and the germs 
sinking to the bottom. The starch and harder portions 
of the kernel remain in suspension in the water, which is 
conducted slowly through long troughs, where the starch 
settles to the bottom and the more glutinous portions 
float ofl[ and are recovered. 

It is now easy to see how these various by-products 
may differ widely. When made up largely of the hulls 
or bran they are characterized by a relatively high pro- 
portion of fiber with comparatively low percentages of 
protein and fat. The presence of the germs increases the 
relative amount of protein somewhat and of the fat very 
greatly. The fine glutinous part, that is finally separated 
from the starch, when unmixed with other materials is 
distinguished by its high content of protein. 

As found in the market, the principal brands are corn 
bran, gluten meal, that comes from the flinty portion of 
the kernel, and gluten feed, which is now a mixture of 
hulls, the gluten part, and the steep water residue. When 
unmixed with other parts of the kernel, the hulls are also 
known as corn bran and the germ portion from which the 
oil has been pressed is called, when ground, germ oil meal. 
The corn bran contains the least protein and the gluten 
meal the most, while the gluten feed and germ oil meal 
occupy a position between these. 

In recent years the practice has been adopted of add- 
ing to the gluten feeds the solids found in what is known 
as the steep water, that is, the water in which the maize 
kernel and its parts have been soaked during the process 
of separation of one part from another. This steep water 
contains all that is soluble in 'the maize kernel or has 



COMMERCIAL FEEDING-STUFFS ' 255 

become so through the treatment it receives, including 
soluble proteins, amino acids, and the soluble mineral 
salts of the corn. This steep water residue darkens the 
color of the feed and renders it acid in varying degrees, 
which at first caused an unwarranted prejudice against 
gluten feeds with these characteristics. 

346. Residues from the manufacture of beet-sugar. — 
An industry apparently now established in the United 
States, the manufacture of beet-sugar, is offering to 
farmers two waste products, sugar-beet pulp and sugar- 
beet molasses. The former is the extracted beet tissue 
from which all the sugars and more or less of other solu- 
ble compounds have been removed. This pulp as it 
leaves the factory has been found to contain an average 
of scarcely 10 per cent of solids. One ton of pulp sup- 
plies, then, not over 200 pounds of total dry substance, 
or perhaps 160 pounds of digestible dry substance. This 
means that it would require six tons of wet pulp to supply 
as much of digestible nutrients as one ton of good hay. 
The solids of the pulp must be regarded as inferior to those 
of the beets before extraction because consisting more 
largely of fiber and gums whose productive value is below 
that of sugar. Experiments at Cornell University in- 
dicated that the pulp is worth about one-half as much 
as corn silage, which would be approximately the rela- 
tion of digestible matter in the two materials. 

Sugar-beet pulp is, however, a useful, succulent food, 
and may be fed to advantage in quantities from seventy- 
five to one hundred pounds daily to full-grown animals, 
provided it can be purchased at a price proportional to 
its value. 

The pulp is not adapted to transportation for long 
distances because of the heavy expense of freight and 



256 THE FEEDING OF ANIMALS 

handling, but is most available for consumption near the 
factories. It may be preserved in pits or silos. 

Dried beet pulp is now on the market. Its protein- 
content is low, and the carbohydrate-content high. The 
rate of digestibility is fairly high. Cattle-feeders should 
bear in mind that the use of this material only intensifies 
the already high carbohydrate-content of the home-raised 
feeds. 

The molasses is generally four-fifths or more dry 
substance and contains from 40 to 50 per cent of sugar, 
which is all digestible and which gives to this product 
its only value for feeding purposes. 

This material has been fed successfully to bovines 
and swine. When given as an addition to coarse foods 
and home-raised grains it obviously should be combined 
with some nitrogenous feeding-stuff like gluten meal 
or the oil meals. 

347. The oil meals in general. — ^Materials of this class 
may properly be regarded as among the standard feed- 
ing-stuffs. Because of their uniformity in quality and 
composition, their general usefulness in compounding 
rations and their value in maintaining soil fertility, 
their use has had the sanction of scientific men and of 
successful practice. The oil meals are so called because 
they are the residues left after the extraction of the oil 
from certain seeds and nuts, among which are cotton- 
seed, flaxseed, hemp and poppy seed, rape seed, sesame 
seed, sunflower seed, coconuts, palm nuts, peanuts, and 
walnuts. Of the residues from these sources, those from 
cottonseed and flaxseed are most common in the United 
States; in fact, no other oil meals have become greatly 
important in our cattle-feeding. A description, therefore, 
of the production of cottonseed meal and linseed meal 



COMMERCIAL FEEDING-STUFFS ' 257 

will not only cover the points of practical interest to 
American feeders, but will serve to illustrate the main 
facts that pertain to the manipulation of these oil 
seeds. 

348. Methods of extracting oils. — It may be stated 
in a general way that two methods have been used for 
removing vegetable oils from seeds, expressing by pres- 
sure and extraction with a solvent. With the first method, 
it was formerly the custom to express the oil from the 
cold crushed seed, but now the seed is more generally 
submitted to heat, either by boiling or steaming, after- 
ward applying the pressure to the w^arm material. More 
oil is obtained by the latter process. The second or 
extraction method involves the use of a solvent, gen- 
erally a light naphtha, which leaves less oil behind than 
either cold or warm pressure. Before extraction the 
crushed seed is heated just as when pressure is used. 

349. Cottonseed meal. — The cotton seed as gathered 
from the plant consists on the exterior of a mass of long 
white fibers that are attached to the outer coat or hull, 
inside of all of which is the kernel or meat. The seed 
is first delinted by running it through a gin, which removes 
the lint or cotton of commerce. After this operation 
there is still attached to the seed a soft down, which 
is subsequently removed and which constitutes what is 
known as *'linters," a short lint that is used in making 
cotton batting. The remaining portion is that from 
which cottonseed oil and certain by-product feeding-stuffs 
are produced. 

350. Cottonseed hulls. — ^The first process in the manu- 
facture of the oil is to remove the hull from the inside 
meat. This is done by a sheller, which breaks the seed 
coat and forces it from the kernel. These seed coats, 

Q 



258 THE FEEDING OF ANIMALS 

which constitute from 45 to 50 per cent of the delinted 
seeds, are known in commerce as cottonseed hulls, and 
are used to some extent as a feeding-stuff. They are 
characterized by a very low proportion of protein and a 
very high content of fiber. Twenty-two analyses show a 
range of protein from 1.6 to 4.4 per cent, and of fiber 
from 35.7 to 66.9 per cent. Such material as this belongs 
with the very lowest grade of coarse fodder, as both 
composition and experience demonstrate. 

351. Extraction of oil from the cottonseed kernels. — 
The hulless kernels make up from 50 to 55 per cent of 
the delinted seed, and from those the oil is obtained. 
These meats are first cooked twenty or thirty minutes 
in large, steam- jacketed kettles in order to drive off the 
water and render the oil more fluid, and then after being 
formed into cakes in wire cloths, they are submitted to a 
pressure of 3,000 to 4,000 pounds to the square inch. 
This removes at least four-fifths of the oil and leaves the 
cakes very solid, which after drying are cracked and 
ground into a fine meal, known in commerce as cotton- 
seed meal. Formerly a ton of ginned seed yielded the 
following quantities of the different parts: 

Poiinds 

Linters 20 

Hulls 891 

Cake or meal 800 

Crude oil 289 

Since the above estimate was prepared the manufac- 
turing process has been so improved that from forty 
to forty -five gallons of oil are now obtained from a ton 
of seed, giving a correspondingly smaller amount of cake. 
Cottonseed meal at the present time is less rich in oil 
than was the case a few years ago. 



COMMERCIAL FEEDING-STUFFS 



259 



352. Composition of cottonseed oil by-products. — 
The composition of the cottonseed oil by-products is 
the following: 

Table LII 













Nitrogen- 






Water 


Ash 


Protein 


Fiber 


free 
extract 


Fat 




Per cent 


Per cent 


Per cent 


Per cent 


Per cent 


Per cent 


Cottonseed 


9.9 


4.7 


19.4 


22.6 


24. 


19.4 


Cottonseed hulls . . . 


11.4 


2.7 


4.2 


45.3 


34.2 


2.2 


Cottonseed kernels . . 


6.9 


6.9 


30.3 


4.8 


21.4 


29.6 


Cottonseed cake . . . 


8.6 


7. 


44.1 


4.9 


21.2 


14.2 



These figures represent the composition of the several 
materials when the separations are fairly complete. 
Cottonseed products are sometimes sold, however, in a 
more or less mixed condition. There has been found 
in the market undecorticated cottonseed meal, or the 
meal with all the hulls ground in without removal from 
the seed. The meal that is free from hulls should be 
light yellow in color and have a slightly nutty flavor. It 
should show few or no black specks, because the presence 
of these indicate either accidental or intentional adul- 
teration with hulls. Cottonseed meal now contains less 
protein than was formerly the case, which means, un- 
doubtedly, that a larger proportion of hulls or lint, or 
both, is present. Cottonseed feed is a finely-ground mix- 
ture of cottonseed hulls and cottonseed meal, and its value 
is less than that of the pure meal. 

353. Linseed meal (oil meal). — ^The original source of 
this feeding-stuff is the flax plant. This plant serves 
a very useful purpose in producing a valuable fiber, 
and oil which now seems indispensable as a constituent 
of paint and a high-class stock-food. Flaxseed, of which 



260 THE FEEDING OF ANIMALS 

the annual production in this country was about 19,500,- 
000 bushels in 1909, contains a very high percentage of oil, 
ranging in the analyses so far made from 22 to 40 per 
cent. The average is variously stated by different com- 
pilers at from 33 to 37 per cent, and the mean of these 
two numbers is probably fairly correct. On this basis 
a bushel of flaxseed, weighing fifty-six pounds, contains 
nineteen and one-half pounds of oil and thirty-six and 
one-half pounds of other substances. 

354. Extraction of linseed oil. — Linseed oil is obtained 
from the seed by both the pressure and extraction methods. 
The oldest method was to subject the cold crushed seeds 
to a heavy pressure, which expressed from 70 to 80 per 
cent of the oil, leaving a cake containing from 10 to 15 
per cent. Later the warm pressure process was intro- 
duced, which consists of moistening the crushed seed, 
heating it to from 160° to 180° F., and submitting it to a 
pressure of 2,000 to 3,000 pounds to the square inch. This 
improvement increased the output of oil from a given 
quantity of seed, the amount expressed being about 
90 per cent of the whole, leaving a cake containing from 
6 to 7 per cent. The latest and most effective process is 
the extraction of the oil by a light naphtha. The seed is 
crushed and heated as in the warm pressure method, and 
the oil is then extracted by repeated leachings with 
naphtha until the residue when dry contains only about 
3 per cent of oil. The naphtha is thoroughly driven from 
this residue with steam so that the resulting meal is 
entirely free from odor and is as palatable as the residue 
from the pressure process. 

355. Old process vs. new process linseed meaL — 
The terms *'old process" and "new process" are now 
applied to linseed meal, the former referring to that made 



COMMERCIAL FEEDING-STUFFS 



261 



by the cold and warm pressure processes, and the latter 
to the residue from naphtha extraction. The composi- 
tion differences between the two are seen in the following 
average of several analyses of each kind which were 
made by Woll : 

Table LIII 



Old process linseed meal 
New process linseed 
meal 



Water 



Percent 

9.4 
9.2 



Ash 



Percent 

5.4 

5.4 



Protein 



Percent 

35.6 
36.6 



Fiber 



Percent 

7.1 

8.6 



Nitrogen- 
free 
extract 



Per cent 

35 
37 



Fat 



Percent 

7.5 
3.2 



These averages show 1 per cent more protein and 3 
per cent less fat in the new process meal. 

The old process samples analyzed by Woll were 
doubtless from the warm pressiu'e methods and do not 
fairly represent the linseed meal which was found in the 
markets when it first came into general use. Four hundred 
and twenty-eight analyses of old process cake compiled 
by Dietrich and Konig, which were made previous to 
1888, show an average of only 28.6 per cent of protein 
and 10.6 per cent of fat. An average by the same authors 
of 179 analyses of the meal shows 30 per cent of protein 
and 9.9 per cent of oil, those samples taken previous to 
1880 being poorer in protein and richer in fat than those 
analyzed after that date. The average of twelve samples 
of linseed cake made prior to 1883 and compiled by 
Jenkins, gives 29.7 per cent of protein and 11.2 per cent of 
fat. There is no question but that the meal now found in 
the markets is considerably richer in protein and poorer 
in fat than that with which American farmers were first 
acquainted. 



262 THE FEEDING OF ANIMALS 

The relative values of the old and new process meals 
are much discussed. Many farmers are prejudiced in 
favor of the former, possibly because anything which has 
been treated chemically is regarded with suspicion when 
considered as a food. No good evidence exists, however, 
that new process meal is less palatable or less healthful 
than the old process product, nor has practice demon- 
strated that in a general way it is less nutritious. 

A very useful inquiry by WoU mto the characteristics 
of the two kinds of meal showed certain differences which 
are interesting in this connection. Two points were 
studied: the digestibility and the property of swelling to 
a mucilaginous condition when stirred up with water. 
Experiments with animals both in Germany and in this 
country have shown a quite uniformly lower coefHcient 
of digestibility for the protein of the new process than 
for the old process, meal. Woll tested this matter by 
artificial digestion with a solution of pepsin, and his 
results verified those secured w^ith animals, the protein 
of the old process sample proving to be 10 per cent the 
more soluble. This difference is believed to be caused by 
the additional cooking with steam which attends the 
driving out of the naphtha from the new process meal, for 
it seems to be well proven that the digestibility of vege- 
table protein is diminished by cooking. American experi- 
ments do not indicate a lower digestibility of total dry 
matter for the new process meal, which is contrary to 
the verdict of German digestion trials. 

The property of swelling to a mucilaginous condi- 
tion is one well known to pertain to flaxseed. This is due 
to mucilage cells found in the seed coat. When this 
mucilaginous matter has once been swollen, it will not 
repeat the process after drying. Woll's tests showed 



COMMERCIAL FEEDING-STUFFS ' 263 

that the old process meal responded to the swelling test, 
but not the new process, a result due probably to the 
steam cooking of the latter. This may serve as a means 
of determining the method used in manufacturing a 
given lot of meal, but probably has no special signifi- 
cance as to feeding value, unless it indicates the new pro- 
cess meal to be less useful in making a porridge for feed- 
ing calves. 

CHEMICAL DISTINCTIONS IN CATTLE FOODS 

The classes of cattle foods as arranged in the previous 
discussion have had reference to several factors, chiefly 
those relating to origin and texture. Chemical facts have 
not been considerd in these divisions. There are, how- 
ever, certain chemical differences among the various 
groups of feeding-stuffs, a knowledge of which is helpful 
in selecting materials for compounding rations. 

356. Coarse foods vs. grains and grain products. — In 
comparing hays, straws, and other fodders with grains 
and grain products there are points of chemical unlike- 
ness which bear an important relation to problems of 
nutrition. In the first place, the nitrogen compounds 
differ. In the grains we find the nitrogen combined mostly 
in the form of true proteins, while in the fodders and 
roots a proportion of it, and sometimes quite a large 
one, exists in amides. This is a point in favor of the 
grains, for the nutritive function of amides is probably 
more limited than that of the true proteins. Again, the 
non-nitrogenous material of the grains is in general 
superior to that of the herbaceous cattle foods. In the 
former, especially in the cereal grains, there is but little 
fiber and the nitrogen-free extract is made up largely of 



264 THE FEEDING OF ANIMALS 

starch and other bodies, whose net value in nourishing an 
animal is quite surely greater than that of fiber and gums 
found in such abundance in the hays and other fodders. 
The work of masticating fibrous materials is greater than 
with sugar or starch, and less is digested. The terms 
protein and carbohydrates do not signify the same com- 
pounds or the same values when applied to different 
feeding-stuffs. 

357. Classification of feeds according to the propor- 
tions of nutrients. — ^The relative proportion of nitrog- 
enous and non-nitrogenous compounds in feeding-stuffs 
is greatly varied. There is no fixed proportion in the 
same species, even, but it varies to some extent with the 
season, period of cutting, and other conditions. At the 
same time, there are differences of composition between 
several groups of feeding-stuffs that are constant within 
not very wide limits, and which it is important to recognize. 

358. Misleading terms for feeding-stuffs. — ^There 
are a few terms that are popularly used to differentiate 
feeding-stuffs which are misleading. For instance, corn 
meal is often spoken of as "carbonaceous" in contrast 
to cottonseed meal, which is called "nitrogenous." It may 
be seen by reference to preceding data that there is a 
higher proportion of carbon in the proteins than in 
starch or sugars. Cottonseed meal is more carbonaceous 
than corn meal, rather than less so. Such a distinction is 
therefore absurd. 

"Heat-forming" is another term often applied to 
foods rich in carbohydrates, while the more highly nitrog- 
enous materials are characterized as "muscle-forming," a 
distinction apparently based upon the facts that carbo- 
hydrates are usually largely burned in the animal body, 
and that the food proteins are the source of the body 



COMMERCIAL FEEDING-STUFFS ' 265 

proteins. But, as a matter of fact, the potential heat 
value of the digestible part of an oil meal is certainly 
greater than that of digestible corn meal. Under certain 
conditions one feeding-stuff is no more fully used than 
the other for tissue-forming purposes, and both may be 
utilized outside of the usual wastes in the production of 
some form of energy, ultimately heat. 

359. Classification of feeding-stuffs. — ^The satisfac- 
tory division of feeding-stuffs into as few as two classes, 
according to their composition, is not possible by the use 
of any terms whatever. Such a division is necessarily 
based upon the relation in quantity of the protein to the 
non-nitrogenous part, and there is an almost uniform 
gradation of foods in protein-content from those contain- 
ing the least to those most highly nitrogenous. Any 
division into groups with reference to the percentage 
amount of protein must be entirely arbitrary and should 
take account of at least four classes of materials, other- 
wise the extremes of each division are too widely apart. 
Probably no more convenient and rational classification 
of grains and grain products can be suggested than the 
one proposed by Lindsey: 

Class I. Thirty to 45 per cent protein, 30 to 45 per 
cent carbohydrates. The oil meals and gluten 
meals and certain distillers' dried grains. 
Class II. Twenty to 30 per cent of protein, 60 to 
70 per cent carbohydrates. Gluten feeds, the lower 
grade distillers' dried grains, dried brewers' grains, 
maltsprouts, buckwheat middlings, and beans 
and peas. 
Class III. Fourteen to 20 per cent protein, 70 to 75 
per cent carbohydrates. Wheat brans and mid- 
dlings, rye bran, and mixed feeds. 



266 THE FEEDING OF ANIMALS 

Class IV. Eight to 14 per cent protein, 75 to 85 per 
cent carbohydrates. Barley, corn, oats, rye, wheat, 
cerealine, hominy, oat feeds, corn and oat chop, 
and corn bran. The fodders and roots properly 
belong with Class IV. 
By reference to these groups it is possible to ascer- 
tain about what place a particular feeding-stuff will 
take in making up a ration, for instance, to what extent 
it will serve as a protein amendment to a mixture of 
materials composed largely of carbohydrates. 

FOODS OF ANIMAL ORIGIN 

360. The principal materials of animal origin that are 
used in feeding domestic animals are milk, dairy by- 
products, and offals from slaughter-houses. They are 
mostly characterized by their large relative proportion 
of protein and their high rate of digestibility. The net 
nutritive value of their solid matter is very high, because 
it is practically all utilized and a minimum amount of 
energy is required for its mastication and digestion. 
Practice has long recognized the peculiar efficiency of 
feeding-stuffs of this class, which is due to the directly 
available forms of the nutrients. 

361. Milk. — ^Whole milk has a greatly varying food 
value according to its proportion of solid matter. Its 
composition is determined by several factors. The milks 
of different species of domestic animals are greatly unlike 
both in their proportions of total solids and in the rela- 
tion in quantity of the different constituents. 

The table of the average composition of the milk of 
several species, given herewith, is taken mostly from 
figures given in Richmond'^ "Dairy Chemistry;** 



COMMERCIAL FEEDING-STUFFS ' 267 

Table LIV. Composition of the Milk of Mammals (Per Cent) 



Species 


Water 


Dry matter 


Ash 


Casein Albumin 


Sugar 


Fat 


Bitch . 
Ewe . . 








75.44 
79.46 

84.04 
86.04 

87.1 
88.2 

89.8 


24.54 
20.56 

15.96 
13.96 

12.9 
11.8 

10.2 


.73 

.97 

1.05 
.76 

.7 
.2 

.3 


6.1 5.05 
5.23 1.45 


3.09 

4.28 

3.13 

4.22 

5.1 

6.8 

6.89 


9.57 
8.63 


Sow 
Goat . 


7.23 
3.49 .86 


4.55 
4.63 


Cow* . 
Woman 


3.2 
1. .5 


3.9 
3.3 


Mare . 


1.84 


1.17 



*Van Slyke. 

The milks are arranged in the order of their richness, 
the dry matter present varying from 24.54 to 10.2 per 
cent. Those containing a high proportion of total solids, 
particularly those from the bitch and the ewe, are espe- 
cially rich in proteins and fat, the percentages of sugar 
being less than half those in the poorer milks. It is note- 
worthy that the proportions of proteins and fats in the 
milk decrease, and the percentage of sugar increases, as 
the total solids diminish. Two-thirds of the solids of 
mare's milk is sugar, the proportion of this constituent 
in the dry matter of an ewe's milk being only about one- 
eighth. 

If we assume that the milk of each species is best 
adapted to its own progeny, it follows that when the 
young of other species is fed the milk of the cow, as 
is so often done, this milk should be modified so far 
as possible to simulate that provided under natural con- 
ditions. When, for instance, cow's milk is fed to a colt, 
it should be diluted and have its content of milk-sugar 
increased; or when lambs are given cow's milk it may 
well be made richer, by the addition of cream, perhaps. 



268 



THE FEEDING OF ANIMALS 



362. Milk of several breeds. — ^The milk of the cow 
varies with the breed, the individual, and the period of 
lactation, and in its use for feeding purposes these varia- 
tions should be considered. 





Table LV 












Ash* 


Solids 


Casein 


Albumm 


Sugars! 


Fat 


Holstein-Friesian .... 
Ayrshire 


.7 

7 


11.8 

12.75 

14.3 

14.5 

14.9 

15.4 


2.2 

2.46 

2.79 

3.1 

2.91 

3.03 


.64 
.61 
.64 
.83 
.65 
.65 


5. 

5.22 

5.79 

4.88 

5.16 

5.44 


3.26 
3.76 


Shorthorn 


8 


4.28 


Devon 


8 


4.89 


Guernsey 


8 


5.38 


Jersey 


8 


5.78 








♦Assumed. 




tCalculated. 









While we have few or no data on the subject, it is 
probable that the same causes operate in affecting the 
milk of all species. 

363. Dairy by-products. — ^These by-products are three 
in number, skim-milk, both from the gravity and the 
separator processes, buttermilk, and whey. Their aver- 
age composition, as taken from compilations by several 
authors, is as follows: 



Table LVI. Composition op Dairy Offals (Per Cent) 



Skim-milk, general average, Cooke 
Skim-milk, gravity, Fleischman 
Separator-milk, Richmond . . . 

Buttermilk, Cooke 

Buttermilk, Vieth 

Whey, Cooke . . 

Whey, Van Slyke 



Water 



90.25 

89.85 

90.5 

90.5 

90.39 

92.97 

93.07 



Total 
solids 



9.75 
10.15 
9.5 
9.5 
9.61 
7.03 
6.93 



Ash 



.77 

.78 

.7 

.75 

.6 



Casein and 
albumin 



3.5 

4.03 

3.57 

3. 

3.6 
.93 
.83 



Sugar 



5.15 

4.6 

4.95 

5.3* 

4.06t 

5. 

5.16 



Fat 



.3 

.75 

.1 

.5 

.5 

.5 

.34 



♦Probably includes the lactic acid, t-80 per cent lactic also present. §Assumed. 



COMMERCIAL FEEDING-STUFFS 



269 



Skim-milk and buttermilk are not greatly unlike in 
richness in solid matter or in general composition. In 
case the skim-milk is sweet, buttermilk differs from it 
because in the latter the sugar has changed partially or 
wholly to lactic acid. Whey is considerably poorer in 
solids than the other dairy by-products and also differs 
from them in the proportions of the. several constituents. 

Skim-milk is the residue left after removing the 
cream. It differs in composition according to the com- 
position of the original whole milk and the thoroughness 
of the creaming. The percentage of solids which it con- 
tains is proportional in a general way to the richness of 
the whole milk. At one time a contrary notion prevailed 
and the skimmed milk of the butter breeds, especially 
the Jersey and the Guernsey cows, was popularly sup- 
posed to be of inferior quality. Numerous analyses have 
been made of this by-product from several breeds, and 
the succeeding figures give the proportion of solids and 
fat in skimmed milk from the gravity process: 



Table LVII 



Holstein 
Ayrshire 
Jersey . 



Solids in 
whole milk 



Per cent 
12.22 
12.98 
15.24 



Skimmed milk 



Total 
solids 



Percent 

9.5 
10.4 
10.5 



Fat 



Per cent 

.52 

.85 
.37 



These figures show most clearly that the Jersey prod- 
uct is more valuable than that from Holstein cows, 
volume for volume. 

Skim-milk is also affected by the manner or thorough- 



270 THE FEEDING OF ANIMALS 

ness with which the cream is removed. The more per- 
fectly the fat is taken out, the less the percentage of solids 
left behind, and the less their unit value as a source of 
energy. For these reasons gravity-process skimmed milk 
is often more valuable for feeding than that from the 
separator, though under the best conditions of skimming 
in both cases the difference is small. 

Buttermilk, which is the residue after extracting 
butter from cream, varies in composition from such causes 
as the composition of the cream and the perfectness of 
the churning. The more fat that is left in it the more 
it is worth for feeding purposes. Its feeding value is 
but little less than that of skim-milk. 

Wliey solids are mostly sugar. In good cheese-making 
practice, whey retains scarcely any of the casein and fat 
of the milk. It therefore takes a place in the ration quite 
different from that of skim-milk, as it is essentially a 
carbohydrate food. 

The dairy offals are peculiarly valuable as food for 
young animals and swine. It is safe to say that for calves 
and pigs no other materials can fully take their place 
in their relation to health and vigor. 

364. Slaughter-house and other animal refuses. — The 
offals from slaughter-houses and from fish, which have a 
somewhat limited use in feeding domestic animals, are 
meat scraps, meat meal, dried blood, and dried and ground 
fish. The materials serve admirably as a supplement to 
the home-raised feeds which are largely of a carbohydrate 
character, especially in feeding poultry and swine. In the 
case of meat-scraps it is desirable to distinguish between 
those having a large proportion of bone and those mostly 
meat. The accompanying analyses display their composi- 
tion, which is subject to great variations : 



COMMERCIAL FEEDING-STUFFS 



271 



Table LVIII. Composition of Slaughter-House and Other 

Refuses (Per Cent) 



Animal meal, N. Y. station 
Meat meal, German analysis 
Fish scrap, German analysis 
Dried blood, Henry . . . 



Water 


Ash 


Protein 


2.2 


38.7 


37.5 


10.7 


4.1 


71.2 


13.9 


31.3 


48.4 


8.5 


4.7 


84.4 



Fat 



13.2 

13.7 

6.4 

2.5 



The meat and fish offals vary greatly according to 
proportion of bone which they contain. The percentage 
of protein is always large, nevertheless. Dried blood is 
much less rich in mineral matter and fat than other 
slaughter-house offals are generally, and the proportion of 
protein is correspondingly larger. All these materials 
are excellent poultry foods w^hen used as a part of the 
ration. They may be fed to swine also as an amendment 
to cereal grains when dairy by-products are not available. 



CHAPTER XV 
THE PRODUCTION OF CATTLE FOODS 

The farmer, in deciding what forage and grain crops 
he shall grow, should take into consideration several 
factors, of which the following are the main ones: (1) 
The adaptability of the various crops to the soil and 
climate; (2) the adaptability of the various crops to the 
kind of business which is to be followed, whether dairy- 
ing, stock-growing, or sheep husbandry; (3) the capacity of 
the various crops for the production of digestible food; 
(4) the protein supply; (5) the maintenance of fertility. 

365. Adaptability of crops to environment. — Con- 
cerning the adaptability of crops to the great variation 
of soil and climate in this country, it is not possible to 
treat extensively in this connection without going too 
fully into questions of agricultural botany. There are 
however, a few general facts worthy of mention. In the 
first place, few farmers have accurate information con- 
cerning the species of grasses which are growing on their 
farms. Only occasionally is one found who carefully 
observes what species are most prosperous under his con- 
ditions. This is equivalent to the statement that but 
little attention is given to the matter of the adaptability 
of forage plants to the environment under which they 
must be grown. While it may be said that nature carries 
on for the farmer more or less of a selective process, it 
must be remembered that the rotation of crops, involv- 
ing of necessity an artificial selection of species, inter- 

(272) 



PRODUCTION OF CATTLE FOODS ' 273 

feres with this process. The old practice of maintaining 
mowing fields for ten to twenty years without breaking 
the sod might allow the grasses most congenial to the 
soil and climate to estabhsh themselves, but successful 
farming on this basis is now scarcely possible. It is essen- 
tial, therefore, especially in dealing with meadows and 
pastures, to know what members of the grass family 
or other forage plants find the environment congenial. 

366. New vs. old species of plants. — It is commonly 
remarked, with much reason, that more is to be gained 
by the proper selection and proper care of the forage 
crops which have maintained successful, though perhaps 
unrecognized, existence among us for years, than by seek- 
ing for better results from some introduced species. No 
cultivated plant possesses qualities that will defend the 
farmer against the evil effects of poor or ill-directed cul- 
ture, and when intelligent, thorough methods prevail, 
many of the familiar species will do for us all we can 
reasonably expect. Occasionally an introduced species 
may serve a useful purpose, as is true of alfalfa, but in 
general a more economical production of cattle foods will 
be reached most surely through an improvement of 
methods in growing what we already have. 

367. Adaptability of crops to kind of animal produc- 
tion. — It is obvious that the home production of feed- 
ing-stuffs must be adapted to the kind of stock kept. 
A herd of dairy cows can hardly be most successfully 
managed on the old basis of exclusive pasturing in the 
summer and exclusive dry food in the winter. To attain 
the best results the pasture must be amended by soiling- 
crops, at least during late summer and early autumn, and 
a succulent food is a decided improvement to a winter 
ration. On the other hand, the successful growing of 

B 



274 THE FEEDING OF ANIMALS 

steers, sheep, or horses requires in many localities only a 
good pasture and plenty of dried fodder and grain, 
although some succulent foods are desirable with any 
class of animals. Every feeder, no matter what his line 
of business, should have at command quite a variety 
of fodders. 

368. Productive capacity of crops. — ^The productive 
capacity of the different crops used as cattle foods is 
greatly unHke. A satisfactory crop of maize or alfalfa 
contains greatly more dry matter an acre than one of 
oats, peas, or any of the usual meadow grasses, and in 
order that land may yield a maximum supply of feeding- 
stuffs it is necessary to step outside grass and grain farm- 
ing, where long rotations are practised and where a 
major part of the farm is kept in meadow grasses and 
only small areas are devoted to cultivated crops. Rapid 
rotation and the use of the more grossly feeding crops 
are necessary to a vigorous development of the resources 
of any land for the maintenance of animal husbandry. 

Other things being equal, the most desirable crop 
is the one producing the largest amount of digestible 
dry matter. This will not be the same crop for all locali- 
ties. In one section it may be maize, in another alfalfa, 
or in another roots. The selection must be determined 
by circumstances, and no rule of general application is 
possible. Of course, other things outside of quantity of 
production are not generally equal. The cost of pro- 
duction varies so that the largest yielding crop is not 
necessarily the most economical. This is a local matter 
also, concerning which no safe general statement can be 
made. It would be convenient if some correct, universal 
standards of production and cost could be formulated 
for the guidance of farmers, but both growth and cost are 



PRODUCTION OF CATTLE FOODS 



275 



much modijBed by locality and other circumstances and 
data are not available, and doubtless never will be, from 
which useful averages may be obtained. 

The most that it is possible to show is the relative 
productive capacity of different crops when the yield is 
what is regarded as highly satisfactory in favorable 
localities under good culture. This is done in the accom- 
panying table. Attention is again called to the fact that 
judgment should be based upon the amount of digestible 
dry matter produced : 

Table LIX 



Alfalfa 

Maize, whole plant 

Red clover, about 334 tons new hay 

Oats and peas 

Timothy, about 2% tons new hay 

Hungarian grass 

Mangolds 

Sugar-beets 

Potatoes 



Yield 
per acre 

fresh 
material 



Pounds 
35,000 
30,000 
18,000 
20,000 
11,500 
19,000 
60,000 
32,000 
18,000 



Dry 

matter 



Percent 
25 
25 
30 
16.2 
38.4 
25 
10 
20 
25 



Dry 

matter 

per 

acre 



Pounds 
8,750 
7,500 
5,400 
3,240 
4,416 
4,750 
6,000 
6,400 
4,500 



Dry 
matter 
digesti- 
ble 



Percent 
69 
61 
57 
65 
57 
67 



85 



Digestible 

dry 

matter 

per 

acre 



Pounds 
5,162 
5,025 
3,070 
2,106 
2,517 
3,182 
5,200 
5,632 
3,825 



The estimates here given may not coincide with the views 
of all as to what constitutes a fair crop, but from the data 
shown, anyone can easily make a calculation on the 
basis of his own estimate. 

369. Crops of high productivity. — The foregoing figures 
emphasize the relative high productivity of alfalfa, 
maize, and roots, as compared with certain cereal grains 
and the meadow grasses. The former crops fill an impor- 
tant place in intensive stock husbandry. Probably no 
species of forage plants are known that are more economi- 
cal sources of high-class cattle food than alfalfa and 



276 THE FEEDING OF ANIMALS 

maize. While the latter crop is no more productive than 
mangolds and sugar-beets when these are at their best, 
the corn crop costs much less in labor. 

Crops of such large productive capacity are espe- 
cially adapted to dairymen located on limited areas of 
high-priced land. They occupy a place in intensive cul- 
ture which will become more and more important as 
grazing and long rotations are replaced by soiling and 
stable feeding during the entire year. 

370. Home supply of protein. — ^The protein supply 
of the farm may be augmented by the growth of legu- 
minous crops, such as peas, beans, alfalfa, and the clovers. 
In so far as climate and soil permit the economical pro- 
duction of this class of fodders, there will be a corres- 
pondingly less necessity for the purchase of nitrogenous 
feeding-stuffs. 

371. Legumes and fertility. — ^The leguminous crops 
are regarded as sustaining an important relation to 
fertility in acting as nitrogen-gatherers, and for this 
reason they are believed to be a valuable adjunct of any 
system of farming. Just what proportion of the nitro- 
gen in a crop of clover, for instance, comes from outside 
the soil is not known, however, either for particular con- 
ditions or as to the average. 

SOILING-CROPS 

372. Soiling-crops a necessity. — The production of 
green crops as an amendment to the pasture, or as a 
substitute for it, is a practice essential to the highest suc- 
cess in dairying on many farms, and is to some extent 
desirable in other branches of stock husbandry. 

There are few pastures, perhaps none, that afford 



PRODUCTION OF CATTLE FOODS ' 277 

grazing in August and September of such a quality as to 
maintain a satisfactory flow of milk. In many instances, 
moreover, farmers owning a limited area of high-priced 
tillable land w^ish to keep the maximum number of ani- 
mals an acre, and to do this they must cultivate soiling- 
crops for stable feeding. 

It is no longer a debatable question, whether or not 
soiling is profitable under most conditions. Unlimited 
testimony can be furnished showing the great gain from 
every point of view of even partial soiling as an amend- 
ment to the pasture. Whether soiling should be sub- 
stituted entirely for grazing is a business matter which 
should be decided according to the conditions involved. 

373. Conditions favorable to soiling. — ^New England 
farmers owning upland rocky pastures in which grow 
native grasses of the highest quality for any class of 
animals could not widely discard them. Such land gen- 
erally absorbs but little capital, and the labor of supply- 
ing food by this method is reduced to a minimum. The 
case is different with high-priced, easily tilled land located 
near good markets. These conditions call for intensive 
farming, and grazing animals on permanent pastures is 
not a part of intensive practice. Under such circum- 
stances the wisdom of a soiling system is clearly indicated. 

374. The economy of soiling-crops. — In the first 
place, much more food is produced on a unit of area by 
soiling than by pasturage. Armsby found that two 
soiling-crops in one season, for instance rye followed by 
corn, yielded five times as much digestible organic matter 
as pasture sod, when the whole growth on the latter was 
plucked without waste, the quantities being, respectively, 
5,845 and 1,125 pounds. It is variously estimated from 
observations in practice that three to five times as many 



278 THE FEEDING OF ANIMALS 

animals can be supported on a given area by soiling as 
by grazing. 

Again, grazing is wasteful because of the imperfect 
consumption of the growth that is made. Much grass 
is tramped down and much is fouled with dung and 
urine. These facts are well understood. Other advan- 
tages besides economy of land and material pertain to 
soiling, such as saving of fences, comfort of the animals 
and an increased supply of manure, but these factors do 
not require discussion in this connection. 

375. Selection of soiling-crops. — Outside of consid- 
erations previously noted, productiveness especially, the 
dairy farmer in selecting soiling-crops must have regard 
chiefly to the number of animals to be fed, the time when 
the crops will be needed, and the number of days required 
for their development. If soiling is adopted in order to 
amend the pasture during the late summer and early fall, 
a limited number of crops will meet the demand. Three 
sowings of peas and oats in late May and early June and 
two plantings of corn, one at the usual time and one two 
weeks later, would furnish a supply of green food when it 
is most likely to be needed. If it is a question of selecting 
crops for a system of complete soiling, nothing more 
suggestive can be offered as to species and succession 
than schemes prepared by Phelps for Connecticut, and 
by Voorhees for New Jersey; 



PRODUCTION OF CATTLE FOODS 



279 



Table LX. Connecticut 

Spec-es of crop Time of seeding 

Winter rye Sept. 1 

Winter wheat Sept. 5-10 

Clover July 20-30 

Grass (from meadows) 

Oats and peas April 10 

Oats and peas April 20 

Oats and peas April 30 

Hungarian June 1 

Clover, rowen 

Soybeans May 25 

Cowpeas June 5-10 

Rowen grass (meadows) . 

Barley and peas .... Aug. 5-10 

New Jersey Scheme 

Species of crop Time of seeding 

Winter rye Sept. 

Winter wheat Sept. 

Crimson clover .... Sept. 

Oats and peas April 1 

Oats and peas April 10 

Mixed grasses Sept. 

Oats and peas May 10 

Cowpeas May 20 

Corn June 1 

Japanese Millet .... June 20 

Cowpeas June 10 

Com June 20 

Soybeans July 10 

Japanese millet .... July 20 

Corn July 1 

Barley and peas .... Aug. 10 

Barley and peas .... Aug. 20 



Scheme 

Approximate 
time of feeding 

May 10-20 
May 20- June 5 
June 5-15 
June 15-25 
June 25-July 10 
July 10-20 
July 20-Aug. 1 
Aug. 1-10 
Aug. 10-20 
Aug. 20-Sept. 5 
Sept. 5-20 
Sept. 20-30 
Oct. 1-30 



Approximate 
time of feeding 

May 1-10 
May 10-20 
May 20- June 1 
June 1-10 
June 10-20 
June 20-30 
July 1-10 
July 10-20 
July 20-Aug. 1 
Aug. 1-10 
Aug. 10-20 
Aug. 20-Sept. 1. 
Sept. 1-10 
Sept. 10-20 
Sept. 20-Oct. 10 
Oct. 10-20 
Oct. 20-30 



The schemes are not practicable for all sections of 
the United States. In the southern and western states 
more especially, they would need modification to suit 
local conditions. 

Alfalfa is not included in either of the foregoing lists. 



280 THE FEEDING OF ANIMALS 

For all sections where this plant can be grown success- 
fully it takes first rank as a soiling-crop. In portions of 
New York, for instance, in favorable seasons it can be 
cut continuously from about the last of May until 
October, and no other crop is more thoroughly relished 
by horses and cattle. It is valuable for horses, even when 
they are doing hard work. 

376. Soiling-crop area and rotations. — ^The area de- 
voted to soiling-crops must be determined by the num- 
ber of animals and the productiveness of the land which 
is to be used. Voorhees states that seven acres, devoted 
to the succession of crops which he recommends, will 
supply twenty-five cows from May 1 to November 1. 
This estimate T^uld hold only when two or three crops 
are grown on the same land in a single season, which 
requires a generous use of manure or of commercial fer- 
tilizers, or of both. The following are suggestions of pos- 
sible rotations: 

{Winter rye, or crimson clover ^Winter wheat 

Oats and peas < Cowpeas 

Soybeans vJ apanese millet 

/Oats and peas /Oats and peas 

\ Japanese millet s Cowpeas 

(.Barley and peas vBarley and peas 

{Winter rye, or winter wheat S Crimson clover 

Com } Com 

Some writers estimate the needed area of soiling- 
crops on the basis of one-quarter to one-half a square 
rod a day for each full-grown animal, the smaller unit 
applying to corn and the larger to oats and peas, and 
similar crops. All this must be a matter of judgment 
based upon the circumstances involved. 



CHAPTER XVI 
THE VALUATION OF FEEDING-STUFFS 

It seems to be very generally supposed that it is 
possible to state fixed relative money values for feed- 
ing-stuffs, and that by comparing these with market 
prices the relation of value to cost may be ascertained. 
Such a state of knowledge is certainly much to be de- 
sired, for it would be of great practical use to feeders. 
For various reasons, however, it is not yet attained, 
and there is little present prospect that it will be. The 
establishment of such relative values for cattle foods, 
as a whole and for general use, is a much more complex 
matter than many suppose it to be, for it touches on one 
side some of the most profound problems of physiolog- 
ical chemistry, concerning which we have only partial 
knowledge. 

377. Basis of assigning values to feeding-stuffs. — 
The problem of assigning values to the classes of nutrients 
in feeding-stuffs may be approached from two directions, 
viz., from the commercial side and from the physiolog- 
ical side. In the first case, the effort would be to calcu- 
late on the basis of the prices of standard commercial 
feeds what is the actual pound-cost of each of the classes 
of nutrients, and thus have a means of ascertaining 
whether a particular feed is selling for less or more than 
the existing market conditions warrant. In the second 
case, the attempt would be to determine the relative 
physiological importance of digestible protein, carbo- 

(281) 



282 THE FEEDING OF ANIMALS 

hydrates, and fats, and this being done, the relative 
agricultural values of feeding-stuffs would be estab- 
lished on the basis of their composition and digestibility, 
thus providing purchasers with a guide for selecting the 
materials costing the least in proportion to their value. 

378. Commercial values of feeding-stuffs. — Experi- 
ment stations have for many years published relative 
commercial valuations of the various brands of fertilizers 
that are in the market. We are not able to establish values 
similarly with cattle foods because of existing condi- 
tions. The dry matter of cattle foods is made up of 
ash, protein, carbohydrates, and fats. We practically 
ignore the ash and base the value of a given food upon 
the other three classes of compounds, which are the 
same in number as the three useful ingredients of 
mixed fertilizers. Now if we could find in the market a 
cattle food supplying only a single ingredient, as is the 
case with fertilizers, we could from its composition and 
market price determine the cost of this ingredient. As a 
rule, however, these classes of nutrients must be bought 
in a mixed condition. All commercial cattle foods, except, 
perhaps, one waste product from sugar production, are 
mixtures in varying proportions of protein, carbohydrates, 
and fats. When we buy one we buy all three. Protein, 
starch, sugar, or oils as found in commerce have become, 
through the necessary processes of separation, too costly 
to be considered for cattle-feeding purposes, and their 
prices in these forms are not a proper basis of calculation. 
If, therefore, a farmer pays $25 for a ton of wheat bran, 
the problem would be what proportion of this sum he 
should assign to the 320 pounds of protein, the 1,240 
pounds of carbohydrates, or the 84 pounds of fats. 

Commercially considered the problem is complex, 



VALUATION OF FEEDING-STUFFS ' 283 

and no simple process will solve it. If we were to deter- 
mine what is the cost of one pound of dry matter through 
the simple division of the price of a ton of feed by the 
pounds of dry matter which it .contains, and then declare 
that all forms of dry matter have equal cost, we would 
get as many prices for protein and starch as there are 
commercial feeds, with no distinction as to the money 
value of these nutrients. Such a method would be absurd. 
It w^ould be a bare assumption to declare that all the 
compounds of a food should have equal market cost. 

379. Valuation of feeds by method of least squares. — 
An attempt was made in Germany, and to some extent 
in this country, to calculate by the "method of least 
squares" what should be considered the cost of protein, 
carbohydrates, and fats as based upon the ton prices of a 
variety of feeding-stuffs. Valuations so derived appeared 
to find favor for a time, and some of our experiment 
stations, following the lead of German chemists, pub- 
lished pound prices for the three classes of nutrients, 
and calculated what commercial cattle foods should cost 
when valued on a common basis. It was soon found, how- 
ever, that, mathematically as weU as practically, most 
absurd results were obtained. 

In the first place, it is already demonstrated that 
the money valuations are often greatly influenced by 
the choice of feeds which shall enter into the calcula- 
tion. Penny, in New Jersey, using cottonseed meal, 
bran, middlings, cob meal, corn meal, and oats, obtained 
certain values for protein, carbohydrates, and fats. Hills 
showed that if Penny had left out the cob meal the value 
for fat would be only half that found, and the value of 
the protein and carbohydrates would be a quarter more. 
Woll obtained certain pound prices with a list of common 



284 THE FEEDING OF ANIMALS 

feeds, but Hills showed again that if WoU had left out 
rye bran these prices would be greatly changed. It 
appears that varying individual judgments as to the list 
of feeds which shall determine values may cause absurd 
differences in the calculated market cost of the nutrients, 
and introducing into the list or withdrawing from it a 
comparatively unimportant feeding-stuff may lower or 
raise the price of one nutrient even one-half. 

A still more serious difficulty arises from the fact 
that often when an apparently typical and proper list 
of feeds is used from which to calculate prices, the 
use of the method of least squares results in giving a 
negative value to one of the nutrients. In several cases 
of this kind the fat was shown to be worth less than 
nothing, a most absurd conclusion. This mathematical 
method is, therefore, not available for the valuation 
of feeding-stuffs, and so far no mathematician has offered 
one that is. 

380. Physiological values. — ^We are left now to inquire 
whether we may not use physiological values, in other 
words the work which a nutrient will perform in the ani- 
mal body, as a starting-point from which to calculate 
relative values. If, for instance, it could be demon- 
strated that protein has a fixed physiological value twice, 
and fats three times, that of carbohydrates, it would 
then be a very simple matter to ascertain what propor- 
tion of the cost of a ton of cottonseed meal should be 
applied to each class of nutrients. To illustrate, a ton of 
high-grade cottonseed meal contains about 590 pounds 
of carbohydrates, 860 pounds of protein, and 260 pounds 
of fat. If these ingredients are assumed to have a ratio 
of value of 1, 2, and 3, then the whole would be equiva- 
lent to 3,090 units of carbohydrates, the cost of one unit 



VALUATION OF FEEDING-STUFFS 285 

of which would be about one cent, when we pay $30 a 
ton for the cottonseed meal. On this basis it would be 
necessary to assign to the protein a cost of two cents per 
pound, and to the fats three cents. If our premise were 
correct we could calculate the cost of the nutrients in any 
one of the feeding -stuffs, and could either ascertain which 
was the cheapest source of each ingredient, or by aver- 
aging could establish a basis for a general valuation. 
Unfortunately no such a premise can be correctly formu- 
lated. We are not yet mse enough to establish fixed 
relative physiological values for the three classes of 
nutrients. 

381. Energy values as a basis of valuation. — It may 
be stated that the energy values of a unit of each of the 
nutrients, protein, starch, and fat have been found with 
apparent accuracy. Why, then, may we not establish 
the relative value of the nutrients on the basis of their 
potential energy, which is measured by the heat they pro- 
duce upon combustion.? Simply because foods have 
another function beside furnishing motive power to the 
animal and keeping him warm. They act as building- 
material. The protein and fat of milk and of the body 
tissues are derived from the food compounds, and the 
actual relative money value of these compounds for con- 
structive purposes is not yet known. No one has yet suc- 
ceeded in actually determining the relative money value 
ot protein, carbohydrates, and vegetable fats as fat pro- 
ducers, and we have no data that allow a definite conclu- 
sion concerning the comparative money worth of the 
muscle-forming function of protein as against the fat- \ 
forming function or energy function of starch. There is 
no promising prospect, at present, of being able to com- 
pare foods on the basis of their physiological importance 



286 THE FEEDING OF ANIMALS 

as a means of determining what should be the relative 
market cost. 

382. Conditions involved in the selection of feeding- 
stuffs. — ^IVIuch useful knowledge is available to the 
stock-feeder as a means of guiding him to an economical 
selection. Some of the important facts to keep in mind 
are: Some feeds carry more nitrogenous matter than 
others; some feeds are largely carbohydrates; cereal 
grains contribute to the ration much the same compounds 
in much the same proportions; the variations of composi- 
tion among the waste products that are in the market as 
commercial feeds; how the coarse foods differ among 
themselves and from the grains; some feeds are better 
adapted than others to a certain class of animals, even 
though of essentially the same composition, and what 
practice and science have taught concerning the mixtures 
necessary to secure an efficient combination of nutrients 
for the work to be done. 

383. Digestibility as a basis for selecting feeding- 
stuffs. — After all this is understood, there may be several 
feeds which are essentially alike in composition and 
nutritive function but which have different prices, and 
there still remains the problem of selecting the most 
economical. It is clear that the best a feeder can do is to 
select the feeds that supply the largest quantity of avail- 
able nutrients for the least money with due reference to 
the class of nutrients desired. If all the feeding-stuffs 
were digested in equal proportions, there would be no 
need of considering digestibility, but this is not the case. 
Large differences in digestibility exist. From 86 to 88 
per cent of the dry matter of the cereal grains, oats 
excepted, is digested, while the digestibility of wheat 
bran, brewers' grains, and oats is on the average only 



VALUATION OF FEEDING-STUFFS 287 

about 62 per cent. Oats are nearly one-fourth less digesti- 
ble than corn, barley, or rye. The refuse products known 
as the oil meals are less digestible than the gluten feeds 
and meals, due, doubtless, to the hulls contained in the 
former. These facts are important and affect the nutri- 
tive value of commercial feeds very materially. 

384. Values based on digestibility. — Farmers should 
base their judgment of the value of feeding-stuffs pri- 
marily upon the proportions of digestible dry matter which 
they contain. This method will probably allow as close 
an approximation to relative values as any which it is 
feasible for the farmers to use now in practice. Doubt- 
less "production" values (see Par. 263) will ultimately 
offer a closer comparison. It is certainly more accurate 
than a comparison of the proportions of total dry matter. 
A hundred pounds of corn contains even less dry matter 
than the same weight of oats, but the digestible material of 
the former is over 20 per cent in excess of that in the latter. 
It is to be remembered, however, that comparisons of 
this kind can be instituted only between feeding-stuffs of 
the same class. The relative values of oil meal and corn 
meal cannot be ascertained in this way, neither should 
the relative values of coarse feeds and the grains be so 
compared. We should not pay for oil meal and corn 
meal on the basis of the quantities of digestible nutrients 
which they furnish, because the nutrients are not identi- 
cal in the two cases. Digestible material which is 40 per 
cent protein cannot be measured by digestible material 
which is only 10 per cent protein. 

385. Digestibility of various feeds. — ^The following 
table shows the digestible material in 100 pounds of 
various feeding-stuffs, as calculated from average com- 
position and digestibility. In the case of hays, the water- 



288 



THE FEEDING OF ANIMALS 



content is assumed to be uniform, viz., 12.5 per cent, 
while the percentages given for the grains are the averages 
found by analysis : 

Table LXI 



Class I — Dried grass plants 
Corn fodder, fresh, average 

Com stover 

Hungarian hay ....... 

Oat straw 

Orchard grass hay .... 

Red-top hay 

Timothy, all 

Timothy, in bloom or before 
Timothy, after bloom . . . 

Class II — Dried legumes 

AKalfa 

Clover, alsike 

Clover, red 

Clover, white 

Class III — Cereal grains 

Barley 

Com meal 

Corn-and-cob meal .... 

Oats 

Oat feed, mainly hulls . . . 
R3'^e meal 

Class IV — Nitrogenous feeds 
16-30 per cent protein. 

Brewers' grain 

Distillers' grains (from rye) — 

Gluten feed 

Maltsprouts 

Wheat bran 

Wheat middlings .... 

Pea meal 




Pounds 
digestible 
dry matter 

in 100 of 
feeding-stuff 



13.8 

34.2 

56.9 

48.6 

49 

52.5 

48.1 

51.6 

45.5 

54.2 
51.6 
50.7 

57.7 



76.5 

74.8 
67.1 
62.3 
30.3 
76.5 



57 

80 
60.3 
54.5 
66 

78.3 



^Assumed. 



VALUATION OF FEEDING-STUFFS 



289 



Table LXI, Continued 





Per cent of 


Pounds of 


Pounds 

digestible 

dry matter 

in 100 of 

feeding- stuff 




digestibility 
of dry 
matter 


dry matter in 

100 of the 
feeding- stuff 


Class V — Nitrogenous feeds 








30-Jf5 per cent protein 








Distillers' grains (from com) — 








Gluten meal 


87 


92 


80 


Linseed meal, old process 


79 


91 


71.9 


Linseed meal, new process . 


78 


90 


70.2 


Cottonseed meal, high grade 


90 


92 


82.8 


Cottonseed meal, low grade 


65 


92 


59.8 



It is fully recognized that these figures cannot be 
taken as absolute relative values. Feeding-stuffs, bear- 
ing the same name, are not always exactly similar in 
composition or in equally good condition. Variations 
in the moisture-content occur, especially with the coarse 
fodders. Even after allowing for all these factors, results 
wdll not follow exactly the quantities of digestible matter 
supplied, because there seems to be a greater adapta- 
bility of some feeds to the needs of a particular species. 
Nevertheless we are forced to conclude that food mate- 
rials of the same class must furnish energy and building- 
material closely in proportion to what is digested from 
them. 

386. Valuations based on protein-content. — Certain 
writers and speakers base the value of nitrogenous feed- 
ing-stuffs, from bran up, entirely on the protein-content, 
and they divide the price by the pounds of protein in a 
ton in order to determine the relative economy of pur- 
chasing this or that material, and the feeding-stuff in 
which the protein cost is the least when so reckoned is 
s 



290 THE FEEDING OF ANIMALS 

regarded as the economical one to purchase. This method 
seems to be absurd, for it is an assimiption that the 
nutritive value of the carbohydrates and fat in commer- 
cial foods may be ignored. The argument is that the 
farm furnishes carbohydrates in abundance, and that 
commercial products should merely serve the purpose of 
reinforcing the protein-supply. If the carbohydrates of 
the farm have no selling value then this argument has 
some force, but this is ordinarily not the case. When 
starch and similar compounds must be purchased as a 
necessary accompaniment of protein, thus causing a sur- 
plus of carbohydrate food, certainly hay, oats, corn, 
barley, or some other home product may be sold to 
relieve this surplus. 

387. Feed values based on feeding experiments. — 
Many practical feeding experiments have been con- 
ducted for the purpose of comparing the different grain 
products as foods for the various classes of animals. Useful 
facts have been reached in this way, especially as to the 
greater adaptability of some materials than others for a 
particular species. But experiments of this kind cannot 
be relied upon to fix relative values of feeding-stuffs for 
milk production, beef production, or for any other pur- 
pose. This is so, first of all, because the errors of such 
tests are so large that we cannot regard their apparent 
outcome as establishing constants. Again, the problems 
involved are too complex and the effect of a given ration 
too dependent upon variable conditions, to allow logical 
conclusions from such experimental data. The difficul- 
ties of the situation will be made clear to anyone by a 
careful study of the whole mass of data resulting from 
feeding tests. Differences appear, some of which are con- 
sistently in one direction, especially in comparing nitrog- 



VALUATION OF FEEDING-STUFFS 291 

enous with carbohydrate foods, but as between mate- 
rials of the same class their comparative values as indicated 
by different experiments are greatly variable, even con- 
tradictory. Any one who endeavors to reach fixed and 
universal valuations on an experimental basis of this 
kind will find himself involved in hopeless confusion. 

388. The verdict of the cow. — Once in a while some 
one talks wildly about leaving food valuation to the 
"old cow." It is sometimes considered a telling argument 
against the chemist's wisdom to declare that he and the 
old cow do not agree. Certainly the cow knows better 
than the chemist what she likes to eat, and it is little use 
to offer her foods she does not relish. Even a chemist 
knows that. If, however, a dozen commercial feeding- 
stuffs were spread around on a barn floor it would be 
much safer to trust an agricultural chemist, especially 
one experienced in stock-feeding, to select a ration than 
any cow ever grown — Holstein, Ayrshire, Jersey, long- 
horned, dishorned, or what not. The cow would probably 
get at the corn meal and stay with it until well on the 
way to a fatal case of indigestion. Her judgment is just 
about as good as that of a child with a highly cultivated 
"sweet tooth," 



CHAPTER XVII 

THE SELECTION AND COMPOUNDING OF 
RATIONS 

There are several factors that must be considered 
in selecting an efficient and economical ration — factors 
which relate to both science and practice. It is gener- 
ally desirable that a food mixtm-e shall be "balanced," 
but this gives no assurance that a ration can be fed 
under particular conditions with satisfactory results. 
Intelligent observation in the barn or stable really takes 
the first place in formulating a method of feeding, which 
is supplemented to a valuable extent by the scientific 
insight of the chemist and physiologist. A ration may be 
chemically right and practically wrong, but, at the same 
time, it is worth much to the feeder to be assured that the 
nutrients which he supplies to his animals will meet their 
physiological needs. Moreover, commercial relations 
such as the prices of feeds and product must be con- 
sidered, and this is a business question and not a scien- 
tific matter. 

389. Palatableness as a factor in feeding animals. — 
A successful ration must be palatable. An agreeable 
flavor is not a source of energy or of building-material, 
but it tends to stimulate the digestive and assimilative 
functions of the animal to their highest efficiency, and is 
a requisite for the consumption of the necessary quantity 
of food. Common experience teaches that when cows or 
animals of any other class do not like their food, they 

(292) 



SELECTION OF RATIONS 293 

"do not do well." Persons sometimes claim that they 
have contracted dyspepsia by eating food which is not 
relished, even food that is nutritious and well cooked, 
and which would be entirely satisfactory to other indi- 
viduals. The situation is still worse when the food is 
undesirable both as to texture and flavor. We have 
reason to believe that animals are susceptible to the same 
influences as man, though perhaps not to the same 
extent. An animal is more than a machine, and is pos- 
sessed of a nervous organism, the existence of which 
should never be ignored. 

One way of stimulating an animal's appetite is to 
feed a variety of materials. Continuous feeding on a 
single coarse food and one grain is not conducive to the 
best results. The various available fodders and grains 
should be so combined as to allow the feeding of all of 
them throughout the season, and avoid the exclusive use 
of one or two kinds for any extended period of time. The 
skilful feeder, then, will not fail to make the ration as 
palatable as possible, and will always consider the idiosyn- 
crasies of appetite of each animal. 

390. Adaptation of rations. — The ration must be 
adapted to the species. This is obvious as relates to 
quantity, but is equally true of the kinds of materials. 
For instance, both poultry and swine generally eat cot- 
tonseed meal with reluctance and with danger to health. 
Wheat bran is less desirable for swine than for other 
species. The horse and the hog are not adapted to rough 
fodder as are the ruminants. It is useless, however, to 
mention at this point other instances of this character, 
or to comment on their importance, further than to 
emphasize the foolishness of trying to bring all species of 
animals to a common basis in the supply of feeding-stuffs. 



294 THE FEEDING OF ANIMALS 

391. Physiological requirements. — The physiological 
requirements of the animal must be considered. A 
ration of maximum physiological efficiency and economy 
must contain the several nutrients in such quantities and 
proportions as will meet the needs of the particular 
animal fed, without waste. This statement is based upon 
facts given elsewhere in this volume relative to the 
demands of the animal body and the functions of the 
nutrients. 

It remains now for us to consider how to compound 
such rations as are desired, or those that are adapted 
in kind and quantity to the requirements which they 
are to meet. Obviously, the first essential for doing 
this is the adoption of standards to which rations should 
conform, for if we do not have these there is no possi- 
bility of concluding whether one food mixture is better 
or worse than another for a particular purpose. 

392. Feeding standards. — Such standards have been 
proposed, which we knew first as German feeding stand- 
ards. The standards that are now accepted are the 
result of numerous and elaborate studies of the balance 
of loss or gain to the animal organism when rations of 
various kinds were fed to animals at rest, at work, and 
when producing meat, wool, or milk, in desirable quan- 
tities. They relate entirely to physiological demands 
without reference to the cost of the rations or to the 
profits which may result from their use. 

The earlier standards were developed chiefly in Ger- 
many but those now most in favor are based upon Ameri- 
can experimental data. 

These standards are variable in two main factors: 
(1) The quantity of available nutrients, and (2) the 
relative proportions of the classes of nutrients. Quan- 



SELECTION OF RATIONS 295 

tity is an essential consideration, for it is obvious that 
enough energy and building-material must be supplied 
to do a given work. It is also obvious that quantity must 
be a variable factor according as the animal is large or 
small, doing hard or light work, giving much or little 
milk, or fattening rapidly or slowly. 

Account must be made of the proportions of the 
nutrients, because protein, for instance, has peculiar 
functions which other nutrients cannot exercise, and 
less than a certain minimum of the proteins in any given 
case, would limit production by just the amount of the 
deficiency. In order for the protein to serve its maxi- 
mum usefulness, its energy should not be encroached 
upon to fill a place equally well or better taken by carbo- 
hydrates; consequently, the proportion of carbohydrates 
must also be considered. 

393. Nutritive ratio. — ^The relative proportion of the 
nutrients of a ration is known as the nutritive ratio. By 
this term is meant the relation in quantity of the digesti- 
ble protein to all the other digestible organic matter 
reckoned in terms of carbohydrates. If we multiply the 
quantity of fat by 2.25 we get its carbohydrate equivalent, 
and if we add this product to the quantity of diges- 
tible carbohydrates present we have the carbohydrate 
value of the digestible matter other than the protein. 
This sum divided by the number representing the pro- 
tein gives the nutritive ratio. For instance, in a ration 
mentioned later there are .94 pound protein, 9.65 pounds 
carbohydrates, and .49 pound fat. (.49X2.25 +9.65) -^ 
.94=11.4. 1: 11.4 is therefore the nutritive ratio of the 
ration. 

A nutritive ratio may be designated as "narrow," 
"wide/* or "medium." These terms do not represent 



296 



THE FEEDING OF ANIMALS 



exact limits to which there is universal agreement. A 
narrow ratio is one where the proportion of protein is 
relatively large, not less perhaps than 1:5.5. A wide 
ratio is one where the carbohydrates are very greatly 
predominant, or in larger proportion perhaps than 1:8. 
Anything between 1 : 5.5 and 1 : 8 may properly be 
spoken of as a medium ratio. 

Merely for the purpose of illustration, three feeding 
standards are given in this connection. These are selected 
from standards proposed by Wolff, as modified by Leh- 
mann. They refer in all instances to animals weighing 
1,000 pounds: 



Table LXII. For 1,000 Pounds Live Weight Daily 




Dry 

sub- 
stance 


Diges- 
tible 
pro- 
tein 


Diges- 
tible 
car- 
bohy- 
drates 


Diges- 
tible 
fat 


Total 
diges- 
tible 
organic 
matter 


Nutri- 
tive 
ratio 


Cow, yield milk, 22 lbs. . 
Fattening steer, 1st per. 
Horse, medium work . . 


Pounds 

29 
30 

24 


Pounds 

2.5 
2.5 
2 


Pounds 

13 
15 
11 


Pounds 

.5 
.5 
.6 


Pounds 

16 
18 
13.6 


1:5.7 
1:6.5 
1:6.2 



These and other standards will be discussed later 
when we come to consider the feeding of the various 
farm animals. Our present purpose is simply to make 
clear the steps necessary to bringing the quantity and 
composition of the ration into conformity with the 
standard selected. 

394. Calculating a ration. — As a means of showing 
the steps involved in calculating what a ration is, and 
how to improve it if necessary, we will assume that it is 
desired to learn whether a food mixture which a milch 
cow is eating is what it should be, and if it is not, how to 



SELECTION OF RATIONS 297 

make it so. The standard ration for a 1,000-pound cow, 
giving twenty-two pounds of average milk, expressed in 
terms of water-free nutrients, has been given in the 
preceding table. 

The first point which requires our attention is that 
this standard is mainly expressed in terms of water-free 
digestible nutrients. This means that we must take 
into account the composition and digestibility of the 
particular feeding-stuffs which enter into a ration, if we 
would discover what it really is supplying of available 
food compounds. It is evident that usually feeders can- 
not have their cattle foods analyzed, and so they must 
resort to the tables of composition and digestibility, 
which are, or may be, in the hands of every farmer. 

395. Calculation of digestible nutrients. — Feeding- 
stuffs, especially fodders, differ within quite wide limits 
in what they contain and in what the animal will dissolve 
from them, according to the species, stage of growth and 
conditions of curing, and an average percentage of pro- 
tein or an average coefficient of digestibility is likely to 
differ widely from the actual facts as pertaining to a 
particular material. All that can be done is to select as 
nearly as possible the figures which have been found for 
feeding-stuffs in the condition of those which are to be 
fed. If the hay is from mature grass, use the composi- 
tion percentages and digestion coefficients given for 
such hay; if the silage is from mature corn, pursue a 
similar course in this case, and so on. Difficulty may be 
met in finding suitable figures, because tables of com- 
position and digestibility are not fully developed and 
classified on the basis of the character of the materials. 

The assumed ration which we wish to discuss con- 
sists of; 



298 



THE FEEDING OF ANIMALS 



Pounds 

Late-cut timothy hay 10 
Corn silage 25 



Hominy chops 
Winter-wheat bran 



Pounds 
. 2 
. 3 



The averages for composition and digestibility, which 
are as likely as any to represent these and other mate- 
rials, are the following: 



Table LXIII 





Composition 




Digestibility 














1 u 








1 o 

C 03 






u 




'S 




^1 




a 
"23 


ti 












4.:) 


a 


1.1 "^ 






« 


Ih ** 






03 


J3 
< 


O 




2;£ 


03 


o 


Si 


•ti IK 

2:2 


(X4 




Per 


Per 


Per 


Per 


Per 


Per 


Per 


Per 


Per 


Per 


Timothy hay, late 


cent 


cent 


cent 


cent 


cent 


cent 


cent 


cent 


cent 


cent 


cut 


14 


3.9 


5.2 


29.7 


45.2 


2. 


43 


46 


59 


51 


Clover hay . . 


15 


7.7 


13.3 


24.3 


37.2 


2.5 


58 


54 


65 


56 


Corn silage . . 


80 


1.1 


1.7 


5.4 


11.1 


.7 


51 


65 


71 


82 


Hominy feed . . 


11 


2.5 


10.4 


4.2 


63.9 


8. 


65 


67 


89 


92 


Wheat bran . . 


10 


6.2 


16.1 


10. 


53.3 


4.4 


77 


39 


71 


63 


Linseed meal, new 






















process . . . 


9 


5.6 


37.4 


8.9 


36.4 


2.7 


85 


74 


84 


93 



The first step in the calculation is to find out what 
percentages of digestible material the components of our 
proposed ration contain, and we shall obtain these by 
multiplying the percentages of composition by the co- 
efficients of digestibility and dividing the product by 
100; that is, if timothy hay contains 5 per cent of pro- 
tein, 45 per cent of which is digestible, then .45 of 5 will 
be the percentage of- digestible protein in the hay. In 
this way the following figures were obtained. The per- 
centage of digestible carbohydrates represents the sum 
of the quantities digested from both the crude fiber and 
the nitrogen-free extract. Tables are now published 
which show percentages of digestible ingredients, and 
which will render this calculation largely unnecessary; 



SELECTION OF RATIONS 



299 



Table LXIV 



Timothy hay 
Clover hay . 
Corn silage 
Hominy feed 
Wheat bran 
Linseed meal 



Digest- 
ible 
protein 



Per cent 

2.2 

7.7 

.9 

6.8 

12.4 

31. 



Digest- 
ible 
carbo- 
hydrates 



Per cent 

40.4 
37.3 
11.4 
58.7 
41.7 
37.1 



Digest- 
ible 
fats 



Per cent 
1. 

1.4 
.6 

7.4 
2.8 
2.5 



Total 
digest- 
ible 
organic 
nutrients 



Per cent 

43.6 
46.4 
12.9 
72.9 
56.9 
70.6 



396. Digestible nutrients in a given ration. — ^The 
second step is to calculate the pounds of digestible nu- 
trients in the quantities of the several feeding-stuffs to 
be used. It is clear, for instance, that 10 pounds of hay 
will contain .10 of the amounts in 100 pounds, so we 
simply need to multiply the percentage of digestible 
protein and so on by 10 and divide by 100 in order to 
learn what 10 pounds of hay will furnish to the animal. 
If we make this computation for each constituent of each 
feeding-stuff, we reach the figures of the following table: 





Table LXV 










Digestible 
protein 


Digestible 

carbo- 
hydrates 


Digestible 

fat 


Total 

digestible 

organic 

matter 


Nutritive 
ratio 


Timothy hay, 10 lbs. . 
Corn silage, 25 lbs. . . 
Hominy feed, 2 lbs. . . 
Wheat bran, 3 lbs. . . 


Pounds 

.22 
.22 
.14 
.37 


Pounds 

4.04 
3.85 
1.17 
1.25 


Pounds 

.10 
.12 
.15 

.08 


Pounds 

4.36 
4.19 
1.46 
1.70 






.95 


10.31 


.45 


11.08 


1:12 



Several authors have published tables showing the 
proportions of digestible nutrients in feeding-stuffs. 



300 



THE FEEDING OF ANIMALS 



397. Correcting an insufficient ration. — ^When we come 
to compare this ration with the standard ration we find 
it is seriously defective in two particulars: it contains 
far too little digestible organic matter and the nutri- 
tive ratio is too wide. 

In order to correct these faults, we must add digesti- 
ble organic matter which contains a much larger pro- 
portion of protein than is found in any of the materials 
so far selected, and we must seek such a supply, in part 
at least, among the highly nitrogenous feeding-stuffs like 
the oil meals and gluten meals. It is easy for one with 
experience to see, also, that all the necessary additional 
organic matter cannot be secured from a highly nitroge- 
nous food without increasing the protein supply unneces- 
sarily. In order to avoid this, the amount of silage may 
be raised ten pounds and still not feed an excessive quan- 
tity. If clover hay is available, it would also be well to 
substitute five pounds of it for five pounds of the timo- 
thy. If, then, we add to the ration three pounds of lin- 
seed meal we shall approximate more nearly to our 
standard. 

Table LXVI 



Timothy hay, 5 pounds 
Clover hay, 5 pounds 
Corn silage, 35 pounds 
Hominy feed, 2 pounds 
Wheat bran, 3 pounds 
Linseed meal, 3 pounds 



Protein 



.11 

.37 
.31 
.13 
.37 
.93 

2.22 



Car- 
bohy- 
drates 



2.62 

1.86 
3.99 
1.17 
1.25 
1.11 

11.40 



Fat 



.05 

.07 
.21 
.15 
.08 
.07 

.63 



Total 
digest- 
ible 
organic 
matter 



2.18 
2.30 
4.51 
1.45 
1.70 
2.11 

14.25 



Nutri- 
tive 
ratio 



1:6.8 



SELECTION OF RATIONS 301 

This ration is still below the standard in quantity, 
but as the relation of the nutrients is approximately 
what is called for, it is only necessary to increase the 
quantities of each component about one-fifteenth in 
order to furnish the animal sixteen pounds of digestible 
organic matter. It is, however, a good ration for cows 
of the smaller breeds weighing from 800 to 900 pounds. 

398. Relation of ration to size of animal. — ^There are 
several points to be considered in this connection. First 
of all, the standard rations are the quantities to be fed 
a day and for 1,000 pounds live weight. This is ordi- 
narily taken to mean that if a 1,000-pound cow requires 
16 pounds of digestible nutrients, an 800-pound cow should 
be supplied with only four-fifths as much, or 12.8 pounds, 
or that a 1,200-pound horse needs 50 per cent more food 
than one weighing 800 pounds. Unfortunately this sim- 
ple mathematical way of calculating rations does not meet 
the plain requirements of practice. The needs of a pro- 
ducing or working animal are not directly proportional 
to its size, for the work done or the quantity of pro- 
duction is the dominating factor. It is certain that feeding 
milch cows or working horses in proportion to weight 
alone contravenes known facts. 

However, we cannot ignore the size of the animal 
in determining the quantity of the ration. Concerning 
this, Armsby says: "The function of the maintenance 
ration is essentially to supply heat to the body to replace 
the constant loss that takes place. Now, Henneberg 
has long ago shown that, in round numbers, over 90 per 
cent of this heat is removed by radiation and evapora- 
tion. Consequently, we should expect the demands of 
the organism for heat (i. e., for maintenance), to be pro- 
portional to its surface (including lung surface), rather 



302 THE FEEDING OF ANIMALS 

than to its weight, and the more recent researches of 
Rubner have confirmed this theoretical conclusion." 
For the purposes of calculation, it is assumed that ani- 
mals are geometrically similar figures and therefore that 
their surfaces are proportional to the cube root of the 
square of their weights. Several steers having weights 
from 1,000 up to 1,700 pounds would need, on this basis, 
amounts of digestible food for maintenance propor- 
tional to figures given in the table below: 

Weight of the animal Proportion of food per 1,000 

approximately pounds live weight 

1,000 pounds 100 

1,100 pounds 96 

1,200 pounds 93 

1,300 pounds 90 

1,400 pounds 88 

1,500 pounds 86 

1,600 pounds 84 

1,700 pounds 82 

For adjusting a maintenance ration to the weight of a 
steer or horse, this method seems to have a plausible 
basis, but it is evidently less applicable to dairy cows or 
rapidly growing or fattening animals, for in these cases 
production and not size must be chiefly considered. 

399. The protein-supply. — ^The matter of the protein- 
supply is important. If we are trying to supply the needs 
of a cow giving twenty-five pounds of milk, or of a steer 
gaining two pounds of body substance daily, there is 
without question a minimum quantity of food protein 
absolutely necessary in each case. These necessary 
quantities are certainly not the same for all individuals, 
but they are not likely to differ widely between single 
animals of the same class and productive capacity. It is 
safe to assert that the earlier protein standards are those 
which it is practicable to feed and which unquestionably 



SELECTION OF RATIONS 303 

generously meet the demands of the class of animals for 
which they are designed. 

400. Earlier protein standards revised. — Through more 
recent investigations, revisions of the earlier protein 
standards have been recommended. These are in gen- 
eral in the direction of a lower minimum of protein, and 
the data secured seem to justify the change. At the same 
time, care should be taken in not fixing the protein mini- 
mum too low, partly because a generous protein-supply 
promotes the general welfare of the animal, and partly 
because of the variable efficiency of the single proteins 
which are found in the different feeding-stuffs in greatly 
unlike proportions. The amount of protein fed in a given 
case should be such as to guarantee a sufficient amount 
for the actual constructive work demanded. (See Par. 275.) 
Probably with certain feeding-stuffs the minimum might 
be lower than with others. It is very evident then that 
the protein-supply in feeding formulas for production 
cannot safely be resolved to the exact limitation of the 
nitrogen compounds needed. The standards that have 
been suggested will be considered in the following pages. 

401. Presence of growth-promoting bodies. — ^The dis- 
covery of growth-promoting bodies attached to cattle 
foods (see Par. 278) leads to the conclusion that rations 
should be selected under certain conditions with refer- 
ence to the presence of these essential compounds. This 
is especially true where animals are likely to be fed on a 
restricted diet, as, for instance, swine, or where by- 
product feeds are used the treatment of which may have 
removed part or all of the food accessories. With animals 
eating the forage portion of plants in large quantities, 
such as the bovines, there is little danger that there will 
be a deficiency in the food of these essential compounds. 



304 THE FEEDING OF ANIMALS 

As these compounds exist in much smaller proportion in 
grain, swine when confined to a restricted grain diet may 
suffer from a lack of such accessory bodies. The addition, 
therefore, to the grain food of swine of some green food, 
such as alfalfa, would appear to insure the animal against 
defective growth. 

Dairy by-products are carriers of both Fat-soluble A 
and Water-soluble B, and the recognized value of these 
by-products in pig-feeding is perhaps partly due to the 
presence of these substances. As time proceeds, the 
knowledge necessary to the compounding of rations with 
reference to the growth-promoting value will doubtless 
be greatly enlarged. 

402. Influence of ration on quality of product. — ^The 
rations should be compounded with reference to the 
quality of the product. Our knowledge of the influence 
of foods upon the quality of meat products is by no means 
complete, but that food has an influence upon the flavor 
of milk and upon the chemical and physical properties of 
butter, seems to be fairly well established. 

403. Home supply of feeding-stuffs to be considered. — 
Rations should be compounded w^ith reference to the 
home supply of feeding-stuffs and to market prices. 
Economy often demands that the materials in hand shall 
be used even if the ration is not ideal. Again, there 
are several protein foods which may be used, and it is 
often only a question of price in determining which should 
be purchased. Notwithstanding the claims of manu- 
facturers, there is no one feeding-stuff essential to the 
health of animals or to the highest quality of the pro- 
duct, so that the feeder may often consider the matter 
of cost and select the cheapest source of protein without 
in any way impairing the ration. 



SELECTION OF RATIONS 305 

404. Selection of a ration largely a business matter. — 
Those who have carefully followed the preceding state- 
ments must have become convinced that the selection 
of a ration which shall be the best possible from a business 
standpoint is not a simple matter. We must always dis- 
tinguish between the combination that is most efficient 
physiologically or productively, and the one that is the 
source of largest profit. It is often the case — perhaps 
generally — that a food mixture which induces a high rate 
of production is the most profitable one to use, but this 
occurs only when business conditions make it possible. 
Many seem to think that if a ration is "balanced" it 
necessarily meets all the requirements for the maximum 
profit, but this is an erroneous view. 

For instance, a farmer somewhat remote from the 
markets may have on hand an abundant supply of hay 
and home-raised grains of such a character that it is 
impossible to compound them so as to conform to the 
accepted feeding standard for milch cows. If the prices 
of dairy products are low, and those of purchased feed- 
ing-stuffs are high, it is entirely possible for the farmer 
to secure more profit from his cows with an "unbalanced" 
ration than with one which has a more nearly correct 
nutritive ratio. 

The western stockman can often afford to waste 
corn on fattening steers rather than use it with greater 
physiological economy by mixing it with purchased 
grains. The cost of the latter would soon offset the 
profits otherwise possible. All this is equivalent to say- 
ing that practical considerations often justify a wide 
departure from the standard rations. Hills states the 
case well when he says: 

"The study of the requirements of the individual 



306 THE FEEDING OF ANIMALS 

animal and the adapting of food to its needs is to be 
preferred to placing the herd, as a whole, upon any 
inflexible ration. The capacity of an animal to receive, 
its ability to produce, the effects of the sundry feeds upon 
the health and condition of the animal, upon its appetite 
and taste, upon the quality of the product, the money 
values of feed, and the profits to be derived from their 
use, are important considerations which do not enter 
into the make-up of the physiological standard, but which 
are vital factors in the feeder's problem. Clearly the 
physiological standards may supplement, and in some 
measure guide, judgment, but cannot take its place." 



CHAPTER XVIII 
MAINTENANCE RATIONS 

It has already been shown that the demands on the 
food vary greatly with different individuals or classes 
of animals according to size and the kind and quantity of 
production. It is proposed to indicate how rations should 
be compounded in order to meet varying conditions and 
demands for production of various kinds, but as prelim- 
inary to this an understanding should be reached as to 
what is required to support the producing organism. 

405. Definition of maintenance ration. — ^A main- 
tenance ration is one supplying the needs of an animal 
without production of any kind and with no loss of body 
substance. To be more specific, when an ox doing no 
work excretes just the quantities of nitrogen and carbon 
that are contained in the food consumed, he is said to be 
eating a maintenance ration. The work done by the 
animal at rest is largely needed in the following direc- 
tions: The chewing of food and its movement along the 
intestinal tract; the muscular action of the heart in caus- 
ing blood circulation; and the metabolic activity of the 
cells in causing the chemical transformation of the nu- 
trients. Some work is also done in moving the body and 
in the effort of standing. The demands upon the food for 
maintenance purposes are therefore largely for the 
support of some form of muscular activity. 

406. Character of maintenance ration. — Nine-tenths 
or more of a maintenance ration may consist of carbo- 

(307) 



308 THE FEEDING OF ANIMALS 

hydrates which, because the income and outgo are bal- 
anced, are used solely as fuel. Only a very small amount 
of protein is necessarily destroyed by a resting animal, 
although a minimum supply is absolutely essential if the 
nitrogenous tissues of the body are to be kept from wast- 
ing. If an animal is not eating protein, the cleavage of 
body protein will go on and urea will continue to appear in 
the urine and in time protein starvation will cause death. 

407. Uses of production ration. — Any ration, fed for 
production, may be looked upon as made up of two parts, 
that which is needed to maintain the animal and that 
which may be applied to growth or the formation of 
milk solids. It is possible, of course, for the produc- 
tion of milk or wool to occiu' when the cow or sheep is 
fed what is really only a maintenance ration, but the 
materials for production under these circumstances are 
furnished at the expense of the body substance. With 
what is regarded as liberal feeding, from one-third to 
one-half of a production ration is needed for mainte- 
nance purposes. It seems fitting, then, to speak of a main- 
tenance ration as a fundamental quantity, a knowledge 
of which is important to both science and practice. It is 
clear that no rational understanding of the uses of food 
can be had, unless we know what amount is required 
simply for maintenance, and the feeder is certainly helped 
to a more intelligent compounding of rations if he has some 
means of judging how large an excess he is supplying for 
production purposes. Occasionally, too, it is desired to 
provide horses and other animals when not at work with 
just enough food to keep them in a uniform condition 
without gain or loss. 

408. Maintenance ration easily provided. — ^No ration 
is more easily provided from the ordinary farm supply 



MAINTENANCE RATIONS 309 

than is that for maintenance, for two reasons: (1) Because 
the quantity of available nutrients which must be eaten 
is so small that this ration may be wholly or mostly made 
up of bulky materials such as corn fodder and hay; (2) 
because investigation has demonstrated that mere main- 
tenance demands a comparatively small amount of pro- 
tein and so this ration may have a wide nutritive ratio 
such as pertains to the nutrients of the more common 
farm products. 

MAINTENANCE RATION FOR BOVINES 

409. Various investigations concerning maintenance 
needs. — ^Experiments, having for their object a determina- 
tion of the daily quantity of nutrients necessary to simply 
maintain animals of this class, were conducted by Heime- 
berg and Stohman with oxen as long ago as 1858. A num- 
ber of rations were fed and the conclusions which were 
reached were based upon the amount of food digested, 
the gain or loss of nitrogenous tissue by the animals, 
their weights, and general appearance. The average daily 
quantities of digestible nutrients which appeared to be 
sufficient to maintain a 1,000-pound ox without growth or 
loss was approximately 8.2 pounds, of which .53 pound 
was protein, the whole having an energy or heat value of 
not far from 15,000 calories. Because of the high tem- 
perature of the stalls used in the above-named experi- 
ments, Wolff estimated later that for winter feeding the 
standard should be 8.9 pounds of digestible nutrients, of 
which .7 pound should be protein, the energy value being 
approximately 16,000 calories, and for a long time 
Wolff's figures were published as the standard main- 
tenance ration. 



310 THE FEEDING OF ANIMALS 

This standard has been revised. The earher experi- 
ments on which it was based furnished data insufficient 
for accurate conclusions, for the only means of judging 
whether the animals were gaining or losing body sub- 
stance were the changes in live weight, which cannot be 
regarded as conclusive evidence. Some of the earlier 
feeding experiments conducted in the United States, 
especially those of Sanborn and Caldwell, indicated that a 
ration based on Wolff's standard was capable of causing a 
material growth of steers, and the accuracy of Wolff's 
figures was called into question. Later observations of a 
more exact character have shown quite conclusively that 
a 1,000-pound steer may be maintained without loss of 
body substances on considerably less than 8.9 pounds, or 
even 8 pounds, of digestible nutrients a day. 

Elaborate experiments by Kiihn from the years 1882 
to 1890, afterwards discussed by Kellner, were regarded 
by the latter as justifying the conclusion that the mini- 
mum quantity of digestible organic matter which will 
maintain a 1,000-pound mature ox at rest is 7.3 pounds, 
.7 of a pound of which should be protein. Later Armsby, 
in presenting the results of experiments of his own in 
connection with a critical review of Kiihn's work, con- 
cludes that "we may place the average maintenance of a 
steer weighing 500 kgs. (1,100 pounds) and receiving 
only a mainly coarse fodder at 13,000 calories of availa- 
ble energy." As Armsby has found one gram of digesti- 
ble matter from roughage to be equal to 3.5 calories of 
available energy, 13,000 calories would equal 7 pounds 
of digestible matter from this source. This would be 
the same as 6.54 pounds for a 1,000-pound animal. 

Still later, Kellner, basing his figures upon extensive 
researches by himself and associates, which were the 



MAINTENANCE RATIONS 311 

most elaborate made up to that time, gave us the 
following as the minimum quantities which will satisfy 
the maintenance needs of mature animals of different 
weights : 

Digestible organic 
Approximate weight substance from 

of animal Energy average meadow hay 

Pounds Calories Pounds 

1,000 10,740 6.75 

1,100 11,520 7.22 

1,200 12,280 7.72 

1,300 13,010 8.18 

1,400 13,720 8.62 

1,500 14,420 9.06 

The researches of Armsby and Fries with the respira- 
tion calorimeter, in a study of the fasting katabolism of a 
steer, furnish us data much more reliable than can be 
secured in any other way. 

410. Fasting katabolism as a measure of mainte- 
nance needs. — ^The exact maintenance needs of a given 
animal are most accurately determined w^hile the animal 
is fasting. When an animal is receiving no food there is 
no cessation of the vital activities. In the maintenance of 
these activities there is necessary a certain amoimt of 
protein cleavage and a sufficient oxidation of organic com- 
pounds to meet the energy needs of the animal. The 
material that is so used is taken from the body structure, 
and by determining the metabolic nitrogen excreted, 
and the gaseous products resulting from oxidation, the 
exact maintenance needs of the animal are ascertained. 
This is a determination of the fasting katabolism of the 
animal body. 

The investigation by Armsby and Fries was conducted 
with a steer which first was fed daily 3.2 kilograms of 
timothy hay, an amount not sufficient to maintain the 



312 THE FEEDING OF ANIMALS 

animal without loss of body substance. The metaboliza- 
ble energy of this insufficient ration was found to be 5.7 
therms, and during the time it was fed, the steer lost from 
his own tissues an amount of protein and fat equivalent 
to 2.4 therms a day. In another period, the steer ate 
5.2 kilograms of the same hay, having a metabolizable 
energy of 9.26 therms, or 3.58 therms more than was con- 
tained in the smaller ration. By feeding the larger ration, 
the use of body protein and fat was reduced to .357 
therms or 2.02 therms less than was the case with the 
smaller ration. It seems, then, that 3.58 therms of 
metabolizable energy in the ration replaced 2.02 therms 
of energy derived from body substance; or, in other words, 
the metabolizable energy in the hay was only 56.5 per 
cent as efiicient as was the energy derived from the 
oxidation of body protein and fat. The other 43.5 per 
cent of the hay energy was used, as we have seen, in the 
way of mastication, digestion, and other internal func- 
tions requiring the use of energy in order to prepare the 
food and transmit it to the tissues. 

411. Distribution of maintenance energy. — ^A study 
of fasting katabolism has made possible not only the 
energy used in maintenance but also the approximate 
determination of the distribution of the uses of energy. 
Zuntz, on the basis of observations made with a fasting 
man, computed that muscular activity, including circu- 
lation, respiration, and the voluntary muscles, used about 
60 per cent of the metabolism and that the internal 
organs, such as the liver, intestines, kidneys, pancreas, 
and salivary glands, used about 40 per cent. 

412. Use of nutrients in fasting metabolism. — The 
studies of fasting metabolism have made it possible to 
measure accurately the relative use of the nitrogenous 



MAINTENANCE RATIONS 313 

and the non-nitrogenous tissues. Determinations with 
many species of animals, including man, swine, dog, 
rabbit, guinea pig, goose, and hen, show that the protein 
katabolism in per cent of total katabojism varied from 7.3 
to 15.6. In all but two cases the range was from 10.8 to 
15.6 per cent. This shows that the energy derived from 
the fat and carbohydrates, largely from the fat where 
this has been stored, is from six to nine times as great as 
from the body protein. 

413. Computation of maintenance needs. — ^The fore- 
going data allow a computation of the metabolizable 
energy that must be supplied in the ration in order to 
meet the maintenance needs of the experimental animal 
that was under observation. 

The larger ration supplied the need of the animal to 
within .357 therm, which was derived from body sub- 
stance. This deficit would be equal to .632 therm of 
matabolizable energy supplied by the hay. The computa- 
tion would be as follows: 

Therms 

56.5 : 100 :: 357 :a:=-=energy 632 

5.3 Idlos hay=energy 9.262 

Energy needed 9.894 

9.262 therms : 9.984 therms :: 5.3 kilos hay : a: =5.655 kilos. 
5.655 kilos =12.44 lbs. hay, or 6.34 lbs. digestible nutrients. 

The animal weighed 822 pounds. If the animal had 
weighed 1,000 pounds, using the formula for body sur- 
face, the figures for digestible nutrients would be 7.21 
pounds. These figures correspond closely to those derived 
from previous investigations. 

Armsby suggests the following maintenance require- 
ments based on production values for cattle, which 
include growing animals: 



314 THE FEEDING OF ANIMALS 

Table LXVII. Maintenance Requirements of Cattle 

Live Digestible Energy 

weighit protein value 

Pounds Pounds Therms 

150 15 1.7 

250 2 2.4 

500 3 3.8 

750 4 4.95 

1,000 5 6. 

1,250 6 7. 

1,500 65 7.9 

414. Maintenance rations for bovines. — In order to 
express a maintenance ration for bovines in terms of hay 
and grain, there are given in this connection several mix- 
tures, based upon energy values in Table XXXIX, which, 
on the basis of average composition and digestibility, 
will furnish fairly closely the necessary protein and energy: 

To Maintain a 1,000-Pound Animal 

23 lbs. mature com silage. 



- i 12 lbs. average timothy hay. ^23 lbs. mature com 

} 4 lbs. wheat bran. 3< 4 lbs. timothy hay 

V 2 lbs. wheat bran. 

/S lbs. com stover, much water. f5 lbs. timothy ha 

5< 6 lbs. clover hay. 4< 5 lbs. clover hay. 

v3 lbs. com-and-cob meal. l4 lbs. com-and-cc 



|8 lbs. com stover, much water. (5 lbs. timothy hay, ripe. 

.4 lbs. com-and-cob meal. 
5. 17 lbs. good mixed hay. 



These combinations are merely illustrative. Many others 
furnishing an equivalent quantity of available nutri- 
ents may be used. Doubtless these various mixtures 
will not show equal efficiency. Ration No. 3 would 
probably be more satisfactory than No. 5, because of 
greater palatableness. All such factors as the proportion 
of grain in the mixture; the stage of growth of the fodder, 
whether early or late cut, immature or mature; the 
amount of moisture present, as in stover; and the com- 
pleteness of preservation, will have an influence upon the 



MAINTENANCE RATIONS 315 

nutritive effect of a ration, and these factors must be con- 
sidered according to the best judgment of the feeder. 
It is possible, without question, to maintain an animal 
on one fodder alone, such as hay, but for several obvious 
reasons it is better to feed some grain. 

The maintenance rations heretofore stated apply to 
a 1,000-poimd animal. For animals weighing more or 
less the quantity should be increased or diminished, but 
not in just the ratio in which the animal varies in weight. 

MAINTENANCE FOOD FOR HORSES 

The general facts which have been presented in rela- 
tion to the function and character of a maintenance 
ration are as applicable to horses as to bovines. It is 
true, however, that rations simply sufficient for main- 
tenance purposes have a very limited application with 
horses, because in nearly all cases they are at least used 
for occasional driving or light work, and even if merely 
"boarded," regular exercise is necessary to their welfare. 

415. Studies of the maintenance needs of the horse. — 
Zuntz, who so thoroughly studied the nutrition of the 
horse, concluded, after a critical survey of the results of 
other men in connection with the elaborate data from his 
own extended investigations, that a 1,000-pound horse 
can be maintained on 6.4 pounds of nutrients, provided 
the total ration contains not more than 3 pounds of crude 
fiber. This means that the nutrients should come from a 
mixture of hay and grain if this minimum quantity is to 
be sufficient. Were only hay to be fed, the necessary 
nutrients would probably exceed the amount named. 

Grandeau in his experiments found that three horses, 
whose mean weight was 852 pounds, were maintained 



316 THE FEEDING OF ANIMALS 

for fourteen months on 17.6 pounds of hay a day, from 
which the three animals digested an average of 6.06 pounds 
of organic matter. Using the method of computation 
already described, this is equal to 6.75 pounds of digesti- 
ble nutrients for a 1,000-pound horse, a result not greatly 
different from that of Zuntz. 

The latest conclusion of Wolff was that a 1,100- 
pound horse should have for maintenance at rest 7.26 
pounds of digestible organic matter daily, exclusive of 
the digested crude fiber, which would be the same as 
6.78 pounds of fiber-free nutrients for a 1,000-pound 
horse. As Wolff regarded the fiber as useless to a horse, 
either for maintenance or for production of work, the 
last figures represent his estimate of the maintenance 
needs of a horse at rest. 

It is proper to remark that Wolff's views as to the 
nutritive value of crude fiber are not generally accepted. 

The following maintenance standards, based on pro- 
duction values, are offered by Armsby : 

Table LXVIII. Maintenance Requirements of Horses 

Live Digestible Energy- 

weight protein value 

Pounds Pounds Therms 

150 3 2. 

250 4 2.8 

500 6 4.4 

750 8 5.8 

1,000 1. 7. 

1,250 1.2 8.15 

1,500 1.3 9.2 

In calculating rations for horses, the coefficient of 
digestibility obtained in experiments with this class of 
animals should be used, coarse fodders, as stated pre- 
viously, not being so efficiently digested by horses as 
by bovines or sheep. 



MAINTENANCE RATIONS 317 

416. Maintenance rations for horses. — ^Accepting the 
standard given on page 316 as the daily requirement of a 
resting horse, the following rations would maintain a 
1,000-pound animal for one day: 

20 lbs. medium quality AC lbs. mixed hay. 

mixed hay. k/ ^ it>s. bran, or 

J 5 lbs. oats, or 
2 ^ 10 lbs. timothy hay. \ 4 lbs. cracked com. 

' ^ ^^'- ^^*'- no lbs. timothy hay. 

SirMu X- it. 1, 6s 10 lbs. carrots. 

10 bs.t.miothyhay. I 3 lbs. com. 

4 lbs. cracked com. 



i 



! 



no lbs. mixed hay. 
10 lbs. medium mixed hay. 7s 10 lbs. carrots. 

43^ lbs. wheat middlings v 4 lbs. oats. 



10 lbs. mixed hay. 
S-N 8 lbs. carrots. 
4 lbs. bran. 



{ 



These rations serve as examples and also indicate 
how with ten or twelve pounds of hay the several grains 
mentioned may be combined to give a maintenance 
ration. It is not wise to feed a horse on hay alone, even 
when doing no work. Ten to twelve pounds of hay are 
enough coarse fodder, which may be supplemented to 
advantage by both roots and grain. 

417. Maintenance food for sheep. — Basing his rec- 
ommendation of maintenance rations for sheep upon Kell- 
ner's production values, Armsby suggests the following: 

Live Digestible Energy 

weight protein value 

Pounds Pounds Therms 

20 23 .3 

40 05 .54 

60 07 .71 

80 09 .87 

100 1 1. 

120 11 1.13 

140 13 1.25 



318 THE FEEDING OF ANIMALS 

This means that seven sheep weighing 140 pounds 
each, or approximately 1,000 pounds, would require 
daily approximately the following quantities of food for 
maintenance purposes: 

Pounds 
Alf aKa hay 20 

or 

Clover hay 14 

Rutabagas 14 

Pea meal 43^ 

or 

Soybean hay 14 

Rutabagas 14 

Wheat bran 5 

These rations supply protein in excess of the standard 
given, but this should not be condemned, as liberal allow- 
ance should be made for the growth of wool. 



CHAPTER XIX 
MILK PRODUCTION 

Milk, like all other animal products, is derived from 
the food. Its secretion stands almost unrivaled as an 
example of the rapid, extensive, and continuous trans- 
formation of the food into animal compounds. In no 
other instance, except perhaps in the case of the earliest 
growth of animals, is so large a proportion of the digested 
nutrients utilized in building new material, or is there so 
intimate a relation between the extent and kind of the 
feeding and the extent and character of the resulting 
product. For these and other reasons, the successful 
feeding of milch cows requires, perhaps, greater expertness 
and a wider knowledge of facts than any other depart- 
ment of animal husbandry. This will appear more fully 
as we continue to develop this subject. 

It is not proposed in this connection to enter into 
an elaborate discussion of the chemistry and secretion 
of milk, for this is presented elsewhere in the series of 
which this volume is a part. It is essential to present 
purposes, however, that we call to mind certain facts 
which are pertinent to a consideration of the food rela- 
tions of milk formation. 

418. Composition of cow*s milk. — ^Milk is a fluid that 
is secreted by all mammals in a gland which w^ith the 
cow is called the udder. It contains water and solids, the 
latter being made up of mineral compounds, proteins, 
fats, and sugar. The average composition of normal 

(319) 



320 THE FEEDING OF ANIMALS 

cow's milk, excluding samples of unusual character, 
according to a compilation by Van Slyke of 5,552 Ameri- 
can analyses is as follows: 

Total solids Ash Proteins Fats Sugar Water 

Per cent Per cent Per cent Per cent Per cent Per cent 

12.9 .7 3.2 3.9 5.1 87.1 

The variations in the composition of cow's milk are 
large, the proportion of water ranging, imder perfectly 
normal conditions, from 84 to 89 per cent, with occa- 
sional analyses entirely outside these limits. The chief 
known causes of such variations are breed, individuality, 
period of lactation, and nervous disturbances. There 
are material daily fluctuations as well, for which no 
reasons can now be assigned. These changes are mostly 
in the proportions of water and total solids, for the com- 
position of the solids, that is, the relative proportion of 
proteins, fats, and sugar, is remarkably constant with 
the same animal. The effect of breed in cows is illustrated 
by averages shown in Par. 362. These variations and 
those due to other causes are important in considering 
the relation of milk formation to nutrition, because the 
food expense of milk is determined, other things being 
equal, not by the volume but by the milk solids elabo- 
rated, for which reason the draft upon the supply of 
nutrients, water excepted, is greater for the secretion of 
100 quarts of Jersey milk than for the same quantity 
of Holstein milk. In studying the economy of milk pro- 
duction, therefore, we should consider the relation of 
food to milk solids and not to milk volume. 

419. Milk secretion. — ^There is no milk in an animal's 
food, that is to say, hay and grain contain no casein, 
butter-fat, or milk-sugar. They do contain nutrients, 
which, when subjected to the vital processes of the animal. 



MILK PRODUCTION 321 

are ultimately transformed into the constituents of milk. 
The mammary gland is not a sieve through which cer- 
tain compounds in the blood are strained into the udder 
cavities, but it is a specialized tissue in which wonderful 
and extensive chemical changes occur. Here, for the first 
time, we find casein, the mixture of compounds known 
as butter-fat, and a sugar imlike any that is found in 
plants, or in any other part of the animal organism. 
Vegetable fats contain glycerides similar to some of those 
found in milk, to be sure, but not in the same number 
or proportions. One fact, moreover, w^hich dairjTnen have 
been slow to recognize in all its significance, is that the 
udder of each individual cow is a law unto itself in the 
characteristics of the milk which it secretes, and is not 
subject in any large degree to control through feeding or 
other treatment that is not actual abuse. 

The manner of milk secretion is something of which 
we know but little, and this is, perhaps, not immediately 
important to the dairyman. The food soiu*ce of the con- 
stituents of milk is, on the other hand, a matter of great 
practical interest, and here we have information more or 
less definite. 

420. Food sources of milk proteins. — ^The previous 
discussion of the fimctions of nutrients must have made 
it clear that the proteins of the milk can have only one 
source, viz., the proteins or closely related compounds in 
the food, a unanimous conclusion which rests upon experi- 
mental evidence as well as upon the universally accepted 
truth that the animal organism does not have the power 
to construct proteins from the simpler compounds used 
by plants for that purpose. 

421. Food sources of milk-fats. — It now seems quite 
certain that the proteins are the only constituents of 

u 



322 THE FEEDING OF ANIMALS 

milk which must have their origin exclusively in the 
nitrogen compounds of the foods, for we have appar- 
ently sound reasons for believing that milk-sugar and 
the butter-fats are constructed, in part at least, from 
carbohydrates. In an investigation at the New York 
Agricultural Experiment Station as to the food sources 
of milk-fat, two cows, both of which gained materially 
in live weight during experiments continuing two months 
or over, produced respectively nineteen pounds and forty 
pounds more of butter-fat than could be accounted for 
fjom the food fat and available proteins. The amount 
of digestible food fat supplied w^as relatively insignificant 
and the secretion of milk-fat seemed to be related in no 
direct way to the protein exchange. These observations 
led straight to the conclusion that carbohydrates are milk- 
fat formers. The extent to which food fat assists in the 
production of milk-fat is not yet determined. While the 
ingested fats appear to pass directly into the milk to some 
extent, it seems quite evident that the larger part of the 
glycerides of milk have their origin in the animal. We 
are not sure, either, whether protein is ever a source of 
milk-fat, but that it is not a necessary source now seems 
to be proved. 

422. The rate of formation of milk solids. — ^A cow 
yielding 6,000 pounds of average milk a year is not 
regarded as an unusual animal. This means, however, 
the annual production of not less than 780 pounds of 
milk solids, an amount at least double the dry matter in 
the body of a cow weighing 900 pounds. When we con- 
sider that this manufacture of new material is carried 
on not only during a single year, but through the entire 
adult life of the animal, we begin to realize how exten- 
sive are the demands upon the food-supply. Still more 



MILK PRODUCTION 323 

striking is the case of high-grade cows yielding annually 
over half a ton of milk solids, and when we remember 
the performance of Duchess Skylark Ormsby, whose 
27,761 pounds of milk produced in one year certainly con- 
tained approximately 3,700 pounds of solid matter or 
more than twice the weight of the cow, we must regard 
the cow as possessing wonderful powers of transmutation. 
Her capacity for the rapid and economical production of 
human food of the highest quality is not equaled by any 
other animal. 

No facts could more forcibly illustrate the necessity 
of liberal and proper rations for the milch cow. 

423. Uses of nutrients in milk production. — ^This 
ration is used in various directions. It must supply the 
raw materials for milk formation, provide for the growth 
of the foetus, sustain the effort of milk secretion, and 
maintain the usual and necessary functions of the animal 
body. The nature and extent of these uses are in part 
quite definitely understood. First of all, the kind and 
quantity of milk solids may be estimated for any given 
case. The daily production of 30 pounds of average milk, 
a performance reasonably to be expected in a good herd, 
involves the elaboration of 3.87 pounds of milk solids. 
Thirty pounds of high-grade milk would contain not less 
than 4.6 pounds of solids. For mere maintenance it is 
fair to assume that the food requirements of the cow and 
steer would not be greatly unlike, disregarding the 
demand for energy utilized in milk secretion, and for the 
material used in the growth of the young. On this basis 
the milk solids and the maintenance needs of a non-pro- 
ductive cow call for about 11.2 to 12 pounds of dry matter 
daily, a quantity utterly insufficient, as experience teaches, 
to maintain a cow giving 30 pounds of any kind of milk. 



324 THE FEEDING OF ANIMALS 

We are led to the reasonable conclusion that, outside the 
building of milk solids, a large expenditure of food energy 
is required to sustain the work of additional food con- 
sumption, the increased metabolic cell activity and 
warming of the extra water and food, which are necessarily 
involved in milk secretion. This view is sustained by the 
results of investigation. In experiments by the writer 
with two cows in full flow of milk, which made only a 
slight gain in body weight, the energy of the digestible 
part of the rations and of the milk was determined. The 
figures reached were approximately as follows : 

Table LXIX 

Cow 10 Cow 12 

wt. 775 lbs. wt. 1,200 lbs. 

Calories Calories 

Energy of digested nutrients .... 27,120 31,300 

Energy of milk solids 8,450 10,200 

Energy not used in milk 18,670 21,100 

Maintenance needs of non-productive 

animal 10,100 13,700 

Balance of energy not accounted for 8,570 7,400 

This energy not accounted for, amounting with the 
two cow^s to more than one-fourth the total energy of 
the nutrients digested, may properly be charged to the 
work of milk production, including of course, food appro- 
priation. Science and practice agree in naming 15.5 to 
16.5 pounds of digestible organic matter as approximately 
the proper daily amount of digestible nutrients for eco- 
nomical milk production with a productive cow of aver- 
age size, much less than which is not to be considered as 
generous feeding. The necessary supply of nutrients will 
vary according to the size and productiveness of the cow. 
Productivity independent of size is a controlling factor. 



MILK PRODUCTION 325 

In general, small cows eat proportionately more food than 
larger ones. 

424. Protein requirements for milk production. — ^The 
question now arises, What proportion of this quantity 
should be protein? The actual amount of proteins in 30 
pounds of average milk, for instance, is about 1 pound. 
If .70 pound is needed daily for mere maintenance then 
1.7 pounds of protein must be used for maintenance and 
milk formation, a quantity which is now regarded as too 
small to sustain such milk production when both food 
economy and the efficiency of the ration are considered. 
With this amount of protein in 16 pounds of total digesti- 
ble matter, the nutritive ratio of the ration would be 
about 1 : 9.5. A ration with as wide a ratio as this would 
be regarded by the great majority of careful experiment- 
ers, and most intelligent dairymen, as less efficient than 
one richer in protein. Few instances are on record where, 
in carefully conducted experiment-station work, other 
conditions being the same, a moderate ration with a 
nutritive ratio of 1 : 5.5 to 1 : 6.5 has not proved to be 
more efficient than one equivalent in quantity but with a 
ratio materially wider. The observations of Atwater 
and Woods among the dairy herds of Connecticut, where 
the owners were induced to narrow the rations they were 
found to be using, gave emphatic testimony as to the 
desirability of a larger proportion of protein than is 
usually supplied in the ordinary home-grown ration. 

There are several possible reasons why the protein 
requirement of a non-productive animal plus the protein 
found in the milk does not constitute a proper standard 
for a milk ration: 

1. The stimulating effect of a generous supply of pro- 
tein upon metabolic activity. 



826 THE FEEDING OF ANIMALS 

2. The use of food proteins for the synthesis of milk 
proteins over and above in weight the milk proteins 
actually formed. 

The partial non-availability of certain food proteins, 
because of their constitution, for reconstruction into 
milk proteins, must now be conceded. (See Pars. 274, 
275.) 

According to the greater part of testimony available, a 
cow of average size and capacity should receive at least 
two pounds of protein daily during the full flow of milk, 
the ration to have a nutritive ratio not wider than 1 : 6.5. 
The nutritive ratio of young pasture grass, perhaps as 
efficient a milk-producing food as we have, is even nar- 
rower than this, a fact which doubtless explains in part 
the large flow of milk from abundant June pasturage, and 
which offers a suggestion for the compounding of winter 
rations. 

425. Relative importance of protein overstated. — 
While the importance of nitrogenous feeding-stuffs to 
a dairy herd is conceded, there is a tendency with certain 
writers to distort the relation of protein to milk produc- 
tion. Their utterances give the impression that in feed- 
ing milch cows, protein is about the only factor to be 
considered. This view is typified by the assertion that 
*'a cow gives milk only in proportion to the protein that 
she receives," a remark which might be made with equal 
accuracy about carbohydrates. It is true that even if 
carbohydrates are supplied in abundance, a depression 
of the protein below a certain limit in a given case will 
diminish the milk flow. It is also true that when sufficient 
protein is fed, a reduction of the carbohydrates below the 
necessary quantity will cut down the milk yield. An ade- 
quate supply of easily digestible carbohydrates is no less 



MILK PRODUCTION ' 327 

important physiologically than keeping up the necessary 
proportion of protein, though the former may be accom- 
plished more easily than the latter because of the usual 
character of home-raised crops. 

FEEDING STANDARDS FOR DAIRY COWS 

The feeding standards for dairy cows, which are 
regarded as embodying our most advanced knowledge, 
have been reached through several stages of development. 
The following are brief descriptions of these stages with 
suggestions as to their imperfections: 

426. Thaer's hay values. — ^Albrecht Thaer, known as 
the father of scientific agriculture, more than a half -cen- 
tury ago suggested "hay values'* as the basis for express- 
ing feeding standards. He calculated the relative values 
of feeding-stuffs in terms of good meadow hay, the neces- 
sary quantities of rations and substitutions of feeding- 
stuffs in them to be based on such values. It is now per- 
fectly understood how crude are such standards for they 
ignore the varying digestibility of feeding-stuffs and the 
necessary relations in the proportion of nutrients. Thaer 
seems to have ignored weight and production as factors 
in determining what a ration should be. 

427. Grouven's milk-feeding standards. — Grouven 
later introduced the factor of weight, and formulated 
eight standards for milch cows to be applied to animals 
weighing from 772 to 1,543 pounds. The matter of vary- 
ing production was ignored. The daily ration suggested 
for cows weighing 1,000 pounds was not irrational, this 
being: Dry matter 28.7 pounds, crude protein 2.76 pounds, 
fat .86 pound, and carbohydrates 14.55 pounds, a ration 
adequate to sustain a generous flow of milk. 



328 THE FEEDING OF ANIMALS 

428. Wolff's feeding standard. — Emil von Wolff seems 
to have been the first one to give a definite recognition 
to digestibility as a factor in calculating feeding stan- 
dards. The standards he proposed were in terms of digesti- 
ble constituents, tlie quantities fed to be directly propor- 
tional to live weight without reference to varying pro- 
ductivity. It was the Wolff standards that first became 
known, and somewhat widely advocated, in the United 
States. Their advocates conceded that they were only 
approximations to actual nutritive needs and chiefly 
valuable as suggestions in the compounding of rations. 

429. Kuhn*s feeding standard.— The fact that Wolff's 
standards made no allowances for varying productivity 
caused them to be severely criticised, and properly so. 
The most prominent critic was Julius Kiihn, who pro- 
posed a basal maintenance ration, additions to be made 
to this somewhat in proportion to the demands for pro- 
duction. The quantities of digestible nutrients recom- 
mended by Klihn ranged between 20 and 23.5 pounds of 
dry matter, 1.5 and 2.4 pounds of digestible protein and 
12 to 14 pounds of digestible amides, crude fiber, and 
nitrogen-free extract, Kiihn holding to the point of view 
of his time that amides function nutritively as do the 
carbohydrates. 

430. The Wolff-Lehman feeding standards. — The 
first standards to recognize, in an extended way, the 
varying nutritive needs of animals according to produc- 
tion, are those known as the Wolff-Lehman, which are 
an attempt to so modify the original Wolff standards as 
to meet the requirements of cows of unlike productivity. 
This was certainly a step. in the right direction. 

These standards have been widely used in the litera- 
ture of animal nutrition in the United States. 



MILK PRODUCTION 329 

431. American feeding standards. — Beginning with 
the feeding standard suggested in 1894 by F. W. Woll 
for dairy cows, several standards have been proposed by 
American authors and experimenters. These proposals 
have been based upon studies of the practice of success- 
ful feeders, or upon more or less extended feeding experi- 
ments. It cannot be said that with a single exception 
these so-called American rations are based upon close 
physiological studies. They are, in fact, mostly modi- 
fications and extensions of the Wolff or Wolff-Lehman 
standard, arrived at through a critical study of what have 
proved in practice to be productive rations. 

It is well to submit these various commendable and 
useful efforts to arrive at practical feeding standards to a 
critical analysis, not only for the purpose of presenting 
the conclusions reached, but also in order to set forth the 
limitations that accompany experimental work of the 
type upon which the conclusions were based. 

432. Well's standard. — This standard is based upon 
the average of about 100 rations in apparently success- 
ful use by American and Canadian farmers. From the 
average was deduced the following daily ration for milk 
production: Dry matter 24.5 pounds, digestible protein 
2.15 pounds, digestible carbohydrates and fat 14.5 pounds. 
This ration is suggested, apparently, on the assumption 
that what is being done by a group of successful feeders 
is a safe guide to the practice of others. In a sense this 
is true, when conditions are similar. This method of 
reaching a conclusion gives no assurance, however, that 
the practice observed is the best that could be devised, 
even though under given conditions it may be found 
profitable. Such a study of existing practice is suggested, 
however. 



330 THE FEEDING OF ANIMALS 

433. standards for milk production based on 
elaborate American feeding experiments. — Three in- 
vestigators, Haecker, Savage, and Eckles, carried on 
extensive semi-practical experiments for the purpose of 
determining the relation between the food of a cow and 
her milk production. These several studies were inaugu- 
rated for practically the same purposes, viz., to deter- 
mine protein demand for milk production and the neces- 
sary quantities of total digestible nutrients. More- 
over, the data secured have been applied differently 
from those derived from previous similar experimental 
work. The final measurements have been based, not 
wholly upon the weight of the animal or upon total milk 
production, but also upon the protein and total nutrients 
necessary for the production of one pound of milk with a 
given percentage of fat. It is on this basis that these three 
pieces of experimental work may be compared. 

Haecker began his records in 1892 and carried them 
through, during definite periods, until 1901. The experi- 
ments upon which his final conclusions are principally 
based were carried on in 1894-1895 for a period of 154 
days, and in 1900-1901 for a period of 113 days, the num- 
ber of cows involved in the first period being 12 and in 
the last period 20. The fodders were analyzed only in 
part, and the digestibility of the various feeding-stuffs 
was calculated on the basis of average digestion coefficients, 
with due reference to the condition of the coarse fodders. 

Savage's work was done from 1909 to 1911. In both 
experiments twelve cows were used in three feeding 
periods of six weeks each, production records being kept 
for five weeks in each period. The fodders were analyzed 
but their digestibility was calculated from average diges- 
tion coefficients. 



MILK PRODUCTION 



331 



The experimental feeding by Eckles was in the years 
1910-1911, and his observations continued for one year. 
The various foods used were analyzed. Digestion experi- 
ments were conducted during two periods, one with three 
animals while they were on a maintenance ration, and one 
with five animals when near the time of maximum milk 
production. Eckles, therefore, secured rather more accurate 
data than was the case with the other two experimenters. 
He was able to calculate more nearly the exact digesti- 
bility of the materials involved in the experimental work. 

With all three of these experiments the amount of 
milk produced was accurately determined and analyses 
made to determine the percentage of fat. By ascertain- 
ing, therefore, the estimated or the actual amounts of 
digestible material fed and the milk production with its 
fat-content, it was possible to calculate the relation to the 
product of the protein and total nutrients digested. The 
following table permits a comparison of the recommenda- 
tions of the three experimenters based on the data secured. 
A fuller table appears later. (See Appendix.) 



Table LXX. Standards for Milk Production as Developed 
BY Haecker, Savage, and Eckles. Protein and Total 
Nutrients for One Pound of Milk.* 



Per 


Haecker 


Savage 


Eckles 


fat in 
milk 


Protein 


Total 
nutrients 


Protein 


Total 
nutrients 


Protein 


Total 
nutrients 


3.4 
3.8 
3.9 
5.3 
5.5 
6.1 


Pounds 

.0444 

.0468 

.0474 

.0558 

.057 

.0606 


Pounds 

.265 
.287 
.292 
.357 
.366 
.392 


Pounds 

.0599 

.0632 

.064 

.0753 

.077 

.0818 


Pounds 

.3115 
.3369 
.3428 
.4209 
.4311 
.4619 


Pounds 

.0469 

.051 

.056 

.048 

.0587 

.072 


Pounds 

.285 
.283 
.298 
.332 
.396 
.505 



*In excess of maintenance needs. 



332 THE FEEDING OF ANIMALS 

The figures here given represent the actual use of nutri- 
ents by the several animals in Eckles' experiment, and 
not the suggested standards. These follow: 





Total 




Total 


Protein 


nutrients 


Protein 


nutrients 


Pounds 


Poiinds 


Pounds 


Pounds 


.05 


.26 


.062 


.36 


.052 


.28 


.066 


.4 


.055 


.3 


.07 


.45 


.058 


.33 


.075 


.5 



These figures are calculated on the basis of the nutrients 
fed minus the nutrients necessary for the maintenance of 
the animal without production. Students of these figures 
should bear in mind that in these investigations the only 
measures of the efficiency of the rations have been the milk 
production and the changes in weight of the animals. It 
is evident that it was not possible by the methods used 
to determine whether there was, with a given animal, a 
gain or loss of body substance other than would be 
indicated by a change in weight, which, as is well kno-wTi, 
is often a deceptive standard of measurement. It should 
be said, however, that probably no practical feeding 
experiments with dairy cows so far conducted give figures 
more reliable as a guide to the feeding of dairy animals 
than those above cited. It will be noted that the increase 
in the protein and total nutrient requirement for each 
increase of one-tenth per cent fat in milk is as follows: 

Haecker Savage 
Pounds Pounds 

Average protein increase for .1 per cent of fat 

in milk 0006 .0008 

Average total nutrient increase for .1 per cent 

of fat in milk 0048 .0056 

434. Requirements of certain feeding standards for 
dairy cows. — In order to apply the various standards for 



MILK PRODUCTION 



333 



feeding dairy cows that have been set forth, it is neces- 
sary first to determine what the standards require. These 
requirements for a 1,000-pound cow giving thirty pounds 
of 5 per cent milk would be as follows: 



Table LXXI 





Maintenance 


Production 


Total 




Protein 


Total 
nutrients 


Protein 


Total 
nutrients 


Protein 


Total 

nutrients 


WoliT-Lehmaii§ 
Haecker . . . 
Savage .... 


Pounds 

.7 
.7 
.7 


Pounds 

8.22 
7.92 
7.92 


Pounds 

2.6 

1.62 

2.18 


Pounds 

9.88 
11.19 
12.14 


Pounds 

3.3 
2.32 

2.88 


Pounds 

18.1 
19.11 
20.06 



In the next table are given the energy equivalents of 
the nutrients required by the several standards: 



Table LXXII 





Maintenance 


Production 


Total 




Protein 


Energy* 


Protein 


Energy* 


Protein 


Energy* 


Wolff-Lehmaii§ 
Haecker . . . 
Savage .... 
Armsbyl! . . . 


Pounds 

.7 
.7 
.7 
.5$ 


Therms 

13.05 

12.573 

12.573 

6.t 


Pounds 

2.6 
1.62 
2.18 
1.35t 


Therms 

15.685 
17.765 
19.273 
11.7t 


Pounds 

3.3 
2.32 

2.88 
1.85t 


Therms 

28.735 
30.338 
31.843 

17.7t 



♦Metabolizable. 

tNet energy. 

iTrue protein. 

§For 27.5 pounds of milk daily, per cent fat not given. 

folder production values used. 

435. Calculation of rations for dairy cows. — In order 
to determine what a ration should be for this particular 
animal, use is made of the following figures showing the 
digestible protein and total digestible nutrients in the 
various feeds entering into the combinations that are 
suggested : 



334 



THE FEEDING OF ANIMALS 



Table LXXIII. In 100 Pounds 



Corn silage . . 
Timothy . . . 
Alfalfa hay . . 
Corn meal . . 
Wheat middlings 
Gluten feed . . 
Cottonseed meal 



Digestible 
protein 



Pounds 
1.1 

3. 
10.6 

6.9 
13.4 
21.6 
33.4 



Total 
digestible 
nutrients* 



Pounds 

17.7 
48.5 
51.6 
83.8 
69.3 
80.7 
75.5 



♦Carbohydrates ■\- (Fat X 2.25) +Digestible protein. 

The next table shows the rations that would meet 
the demands of each of the five standards that have 
been suggested, three of these rations corresponding to 
the several standards for feeding a 1,000-pound cow giving 
thirty pounds of 5 per cent milk: 





Table LXXIV 












Wolff- 
Lehman 


Haecker 


Savage 


Armsby 




g 

1 


Diges- 
tible 
nutrients 


a 
o 


Diges- 
tible 
nutrients 


o 
'■+3 


Diges- 
tible 
nutrients 


o 

1 


Diges- 
tible 
nutrients 




Lbs. 


Lbs. 


Lbs. 


Lbs. 


Lbs. 


Lbs. 


Lbs. 


Lbs. 


Silage 


40 


7.08 


40 


7.08 


40 


7.08 


40 


7.08 


Timothy hay 






, , 






. 


8 


3.88 


Alfalfa hay 


6 


3.09 


8 


4.13 


8 


4.13 






Corn meal 


4 


3.35 


6 


5.03 


5 


4.19 


6 


5.03 


Wheat middlings . . . 






3 


2.08 


1 
3.5 


.69 

2.82 


4 
2 


2.77 


Gluten feed 


3 


2.42 


1.61 


Cottonseed meal . . . 


3 


2.26 


1 


.75 


1.5 


1.13 






Roughage 


46 


, , 


48 




48 


. 


48 




Grain 


10 




10 




11 




12 




Protein 




3.01 


, 


2.44 




2.92 


, , 


1.85* 


Digestible nutrients, total 


. . 18.2 




19.1 




20.04 


• • 


20.37 



♦True protein. 



MILK PRODUCTION 



335 



It is to be noted that these several rations do not 
differ essentially in quantity but show some variations in 
the proportions of the several ingredients in order to 
reach an adjustment with the protein requirement. The 
quantities of the several feeds in the Armsby standard 
are based upon the production values which he has set 
forth. (See Par. 263.) The Wolff-Lehman ration is based 
upon the standard for a 1,000-poimd cow giving 27.5 
poimds of milk, the fat content not stated. 

It should be remarked that these rations w^ould be 
regarded by practical feeders as sufficiently generous. It 
is a question whether the amount of protein required by 
the Wolff-Lehman and Savage standards are not imneces- 
sarily generous, a point to be considered when protein 
feeds are more costly than feeds bearing a large propor- 
tion of carbohydrates. 

436. Suggested practical rations for dairy cows. — 
The following are suggested as practical rations for cows 
of moderate size and fairly large productive capacity: 



'10 lbs. clover hay. 
35 lbs. com silage. 

2 lbs. hominy chops. 

4}/^ lbs. wheat bran. 

23^ lbs. linseed meal, N.P. 

'' 6 lbs. clover hay. 
10 lbs. mixed meadow hay. 
25 lbs. mangels. 
3^ 3 lbs. com meal. 
2 lbs. wheat bran. 
2 lbs. brewers' grains. 
2 lbs. gluten meal. 



4< 



10 lbs. mixed meadow hay. 
40 lbs. com silage. 

4 lbs. wheat middlings. 
3 lbs. maltsprouts. 

. 1 lb. gluten meal. 

10 lbs. com stover. 

5 lbs. alfalfa hay. 
25 lbs. sugar-beets. 

3 lbs. com-and-cob meal. 
3 lbs. buckwheat middUngs. 
^-13/^ lbs. cottonseed meal. 



'12 lbs. clover or alfalfa hay. 
30 lbs. com silage. 

4 lbs. ground oats. 

3 lbs. ground peas. 

2 lbs. brewers' grains. 



336 THE FEEDING OF ANIMALS 

These rations may be criticized on the ground that 
they are too small to sustain heavy milk production. 
This would be a ;ust criticism for cows of large capacity 
that are furnishmg high-priced milk. 

It is the writer's opinion that a majority of cows not 
over 1,000 pounds in weight, maintamed under ordin- 
ary business conditions, will not render larger profit from 
heavier rations. 

437. The sources of commercial protein for milk pro- 
duction: the home supply. — ^The dau-yman has constantly 
to face the fact that from the usual list of home-grown 
feeding-stuffs it is difficult to make up a ration through- 
out an entire season with a nutritive ratio much narrower 
than 1:8, and a proportion of protein even as high as 
this requires a generous admixture of clover in the hay, 
and the use of more or less oats or peas in the grain ration. 
It should not be forgotten that the plants used for for- 
age crops are generally not harvested until they are 
approaching maturity, and as the later growth of most 
plants is largely due to the formation of non-nitrogenous 
compounds, the hay and other fodders stored for winter 
feeding are comparatively poor in nitrogen compounds. 
On those farms where the hay crop comes largely from 
the true grasses, like timothy and red-top, and where the 
corn crop is a prominent feature, a home-raised winter 
milk ration having a maximum efficiency for each unit of 
dry matter consumed is not possible. On the other hand, 
where alfalfa and clovers constitute a good proportion 
of the hay, and where generous areas of peas and oats 
are grown, a ration compounded from home resources 
may have a high milk-producing efficiency. 

438. Commercial protein.— It must be confessed, 
however, that most dairy farms are lacking in a proper 



MILK PRODUCTION 337 

home-raised supply of the more nitrogenous feeding- 
stuffs, and as nearly all dairjTnen depend to come extent 
upon purchased grain, it is a quite prevalent custom for 
them to seek those by-products that will strengthen the 
protein side of the ration. It is unquestionably true that 
farmers should be more independent of the markets, and 
they certainly may be if an intensive system of cul- 
tivating well-selected crops is adopted; but so long as 
more or less grain will certainly be purchased, it is wise 
to consider the matter of selecting commercial protein 
feeds for dairy cows. Those from which it is possible to 
choose are the oil meals, distillers' grains, the gluten 
meals and feeds, brewers' grains, maltsprouts, peas, and 
buckwheat middlmgs. The offals from the milling of 
wheat, while somewhat more nitrogenous than the cereal 
grains, cannot be considered as an abundant som*ce of 
protein, although they are excellent components of a 
milk ration. 

439. No single protein food essential. — ^Notwith- 
standing the claims which trade interests may make to 
the contrary, no one of the above-mentioned feeding- 
stuffs is alone essential to the economical production of 
the best of milk. There is no single food or any one com- 
bination of foods that is always best for dairy cows. 
Apart from certain considerations which will be discussed 
later, a selection of the source of commercial protein is a 
matter of availability and of relative market cost. For 
instance, if gluten meal were to cost $30 a ton, few 
buyers could afford to pay $35 for linseed meal to feed in 
any considerable quantity. If prices were reversed, oil 
meal should be selected. Both oil meals and gluten prod- 
ucts may be ignored if buckwheat middlings or the 
brewers' residues are available at more favorable prices. 



338 THE FEEDING OF ANIMALS 

It is simply necessary that the grain ration shall con- 
tain protein in sufficient quantity and proportion, and 
shall be made up of a variety of materials, better not 
less than three kinds, all of which should be palatable 
and exert no deleterious influence upon the milk or its 
products. There are few grain products that cannot be 
used successfully in grain mixtures, even though they 
are undesirable when fed alone. 

THE KELATION OF FOOD TO THE COMPOSITION AND 
QUALITY OF MILK 

The character of milk is believed by many to be inti- 
mately related to the kind and quantity of food from 
which it is produced, i. e., that a dairyman who is pos- 
sessed of sufficient knowledge may, by variations in the 
rations, cause material changes in the composition of 
the milk of his herd. This is equivalent to believing that 
thin milk or rich milk, milk rich in fats and poor in casein 
or the reverse, may be obtained at the will of the feeder. 
Such a view in its extreme form is very far from the 
truth. While below a certain limit for each cow the quan- 
tity of milk is mostly determined by the ration, other 
factors, such as breed, individuality, and period of lac- 
tation, are much more potent than the food in fixing 
its composition. 

In discussing this topic, it must be confessed, first 
of all, that the experiments touching its several phases 
have not furnished information satisfactorily definite 
and conclusive in all respects. The testimony arrived at 
is more or less confusing and contradictory. There are 
several directions in which it has been necessary to look 
for the effect of food upon milk: (1) Effect upon composi- 



MILK PRODUCTION 339 

tion: (a) in changing the proportion of water and total 
sohd matter; (6) in changing the relative proportions of 
proteins, fat, and sugar, (c) in changing the constituents 
of the fat. (2) Effect upon flavor. 

440. Effect of food on the proportion of milk solids. 
— In discussing the effect of food upon the proportion 
of total solids, the question is. Can the richness of milk 
be modified by changes in the ration? For instance, is 
the milk from a very generous food-supply richer than that 
from a moderate or scanty ration, or will a highly nitrog- 
enous ration cause a secretion of milk with a higher per- 
centage of solids than a ration poor in protein.? It would 
probably be generally conceded that if variations in milk 
are caused in these ways, they are small as compared to 
those due to breed characteristics or to individuality. 
Can we bring about variations sufficiently large to be 
important? This question has been much discussed and 
much investigated from the work of Kuhn in 1868 down 
to the present day. Many experiments have been con- 
ducted for long periods and short periods in which very 
moderate rations have been compared with very large 
ones, highly nitrogenous foods with those of a low pro- 
tein-content, dry with green or succulent materials, and 
grains of the same class with one another, and, in a great 
majority of cases, the verdict has been that no consist- 
ent relation appears to exist between the quantity or 
character of the ration and the proportion of solids in 
the milk, a conclusion that has run counter to a very per- 
sistent popular belief. In some cases, a temporary change 
has appeared in the milk immediately after a violent change 
in the ration, but in most instances of this kind, there was 
very soon a return to the animal's normal product. In 
a small proportion of experiments, the milk appeared to 



340 THE FEEDING OF ANIMALS 

sustain a permanent, though not extensive, modification. 
The weight of testimony bears out the statement that 
the content of soUds in milk cannot be modified at will 
by the farmer, but is largely determined by causes not 
under his control, such as breed and individuality, 
although feeding and treatment, especially the latter, 
have more or less influence upon the character of the 
milk secreted. It is possible, even probable, that continu- 
ous feeding, either very poorly or very highly, may bring 
about in time a permanent change in a cow's milk, but 
today no one is wise enough to point out a way of defin- 
itely controlling this product through the food. 

441. Effect of food upon the constitution of milk 
solids. — In the discussions relative to feeding dairy cows, 
another point has received much attention, viz., the 
effect of foods upon the proportions of the constitu- 
ents which make up the dry matter of milk. A popular 
notion has prevailed that it is possible to "feed fat into 
milk," having its origin in part, perhaps, in miscon- 
ceptions as to the manner of milk formation. If the 
mammary gland served simply to capture the unchanged 
constituents of the food, then it might be reasonable to 
expect the milk to partake of the character of the digested 
nutrients and be "fat" or "lean" according to the pro- 
portions of proteins and fats supplied to the animal. 
When, however, we consider that this gland has the func- 
tion of transforming the raw material of the food into a 
milk which is characteristic of the breed or of the individual 
in accordance with somewhat fixed constitutional limi- 
tations, and that from the same food the Jersey cow will 
make Jersey milk and the Holstein cow Holstein milk, 
that a cow which starts in life giving thin milk is never 
transformed into a producer of rich milk, we can easily 



MILK PRODUCTION 341 

understand the general failure to find a recipe for feed- 
ing fat into milk. Experimenters who have added large 
quantities of fat or oil to a ration have in all but a very 
few instances failed to permanently, or even tempora- 
rily, increase the percentage of fat in the milk solids; 
and, on the other hand, rations rich in protein do not 
appear to cause a larger relative amount of proteins in 
the milk-dry substance than rations w^ith a wide nutri- 
tive ratio. As a matter of fact, after years of investiga- 
tion and intelligent observation, we are not able to afiirm 
that the proportion of fat to other milk solids is in any 
way related to the feeding of the cow, and if apparent 
exceptions to the general experience have been noticed, 
no one has discovered any general method or law whereby 
the exception may be made the rule. 

Physiological disturbances may result from feeding a 
ration so selected or treated that it is greatly deficient 
in certain nutrients. In experiments by Jordan, Hart, 
and Patten, the deficiency of phosphorus compounds 
in the rations of milch cows appeared to cause, among 
other effects, a marked diminution of the proportion of 
fats in the milk solids. By-product feeding-stuffs simi- 
larly deficient might cause a similar result. 

442. Influence of food on the milk-fats. — It should 
not be inferred from the previous statements that none 
of the compounds of the food enter the milk as such, or 
that the qualities of the milk are in no way influenced 
by the character of the ration. Such conclusions would 
not be consistent with the outcome of numerous investiga- 
tions. While it has become quite evident that the com- 
position of butter, and therefore its qualities, such as 
hardness and melting-point, are sometimes materially 
modified by the cow's food, it is not now possible to state 



342 THE FEEDING OF ANIMALS 

with any definiteness just what influence all the various 
feeding-stuffs have upon the chemical and physical 
properties of butter. Experimenters are fairly unani- 
mous, however, in concluding that the liberal feeding 
with cottonseed or cottonseed meal has the effect of 
raising the melting-point of butter and of diminishing 
the percentage of the volatile fatty acids. On the other 
hand, when gluten meal rich in oil has been introduced 
into the ration in generous proportion, the butter has 
been found to melt at a lower point, and appeared softer. 
Certain chemical reactions indicate that this decrease in 
the melting-point has been accompanied, in some cases at 
least, by an increase in the butter of olein, a fat which is 
a prominent constituent of olive oil, and is liquid at 
ordinary temperatures. One set of experiments, where 
gluten meal with different proportions of oil was used, 
appears to warrant the conclusion that the softening of 
the butter from feeding this material is not marked when 
its percentage of fat is small, as is the case with some 
brands of gluten meal at the present time. The conclu- 
sion which has been reached as a result of some experi- 
ments, that gluten meal causes softer butter than corn 
meal, the fats and other compounds in the two feeds 
being similar in kind, is wholly irrational unless we 
conclude that the larger quantity of fat fed in the former 
is the cause of its specific influence. In a few cases where 
various oils were fed in liberal quantity the butter is 
reported to have varied in ways corresponding to the 
composition of the oils, a result not at all improbable. 

In looking over the record of investigations along 
this line it is found that food rich in sugar and other 
soluble carbohydrates is credited with producing soft 
butter, potatoes are charged with the same effect, and 



MILK PRODUCTION 343 

even cooked or sour foods are said to have a peculiar 
influence. Some writers go so far as to present lists 
of feeding-stuffs in the order in which they increase the 
volatile fatty acids, but such definite representations must 
at present be taken "with a grain of salt." In most 
instances, no relation is established between the effect 
observed and the market value of the butter. In fact, it 
is distinctly asserted by one or two experimenters that 
there is no clear relation between the melting-point and 
hardness. It seems quite probable that when the ration 
includes a variety of grain foods, practically the entire 
list of feeding-stuffs may be utilized under proper con- 
ditions without damaging the market value of the butter 
for local consumption. 

443. Effect of food on the flavors of milk and its 
products. — It is not possible with our present knowl- 
edge to establish a relation between the flavors of dairy 
products and the presence of definite compoimds. What- 
ever causes flavor in milk or butter is generally present 
in such minute quantities that even if the nature of the 
substance were kno"s\Ti the determination of its amount 
would be beyond the skiU of the chemist. Milk satis- 
factory to the critical taste and smell may be so simply 
because bad flavors are absent, or there may be present 
the positive influence of some constituent of the ration. 
It is probably safe to assert that compounds in the food 
pass into the milk as such, and the superiority of June 
butter, if such exists, may be due to the almost impon- 
derable volatile odors which are derived from the young 
grasses. Nothing is more certain than that the dele- 
terious odors of certain foods and those that pertain to 
the stable are often absorbed by milk, as, for instance, 
when cabbage, turnips, and onions are fed. 



344 THE FEEDING OF ANIMALS 

It is generally believed that odors or flavors from 
the foods which affect milk in so marked a manner may 
enter it in two ways, by transference through the animal 
and by absorption from the air of the stable. Unfortu- 
nately, however, the various views which are accepted 
regarding this matter are not based upon satisfactory 
experimental evidence. Some farmers declare in most 
positive terms that they can feed turnips to their cows 
with no harm to the quality of the butter, while others 
assert that this cannot be done. It is claimed that the 
time of feeding, whether just before or just after milk- 
ing, has a marked influence upon the extent to which 
turnips and similar materials impart a flavor to the milk. 
Concerning all these points, we have but little evidence 
other than the somewhat loose observations of practice. 

The results of certain experiments are worthy of men- 
tion in this connection. King and Farrington, of the Wis- 
consin Experiment Station, declare that their experi- 
ments show beyond question that when silage is fed 
before cows are milked a sweetish flavor is imparted to 
the milk, and that such a flavor is not detected when the 
silage is fed after milking. These experimenters also 
placed milk within a silo exposed to the air for an hour, 
and silo air was forced through the contents of some cans. 
In seven out of twenty tests no silage odor could be 
detected, and it was less in any case than when silage was 
fed before milking. 

Canadian experiments on the effect of feeding tur- 
nips seemed to warrant the conclusion that the mere 
presence of a strong turnip flavor in the stable did not 
affect the milk, and that when the turnips were fed in 
small quantity (one peck) daily no flavor was imparted, 
but that when one bushel or more was given the flavor 






'l^^liliiiS! 




MILK PRODUCTION 345 

appeared whether the turnips were fed before milking 
or after. On the other hand, in a Norwegian experi- 
ment as high as 2.8 bushels of turnips were fed to cows 
daily and no turnip taste could be detected in the milk. 
The cows were fed in one place and milked in another, 
and so the experimenter concluded that when this taste 
is observed it is due to absorption by the milk after it is 
drawn. That warm milk may absorb odors is shown by 
Russell. These observations illustrate fairly the some- 
what inconclusive state of the testimony on the points 
in question. 



CHAPTER XX 
FEEDING GROWING ANIMALS 

A DISCUSSION of rations for growing animals relates in 
large part to the uses of food for constructive purposes. 
The formation of bone and soft tissue proceeds rapidly 
in the young organism, the nutrition of which must be 
adapted in kind and quantity to large demands in this 
direction. This is true of all young domestic animals. 

444. The requirements for growth. — ^The actual daily 
increase in live weight of a well-nourished calf may be as 
great as that of a mature steer when liberally fed. It is 
not unusual for the former to gain two pounds a day in 
weight, and 1.5 pounds is less than would be satisfactory. 
It is possible to calculate approximately what this growth 
w^ould require of actual dry matter. The only analysis 
of a calf's body which is available is that made by Lawes 
and Gilbert, from which it appears that the entire animal 
when fat has approximately the following composition: 

Water Ash Protein Fat 

Per cent Per cent Per cent Per cent 

64.6 4.8 16.5 14.1 

A gain of 1.5 to 2 pounds live weight means a storage of 
not less than .24 to .33 pound of dry protein in the 
animal's body, and the laying on, when the animal is fed 
for fattening, of .21 to .28 pound of actual fat. Here, 
then, is an actual daily increase of dry body substance 
of .45 to .61 pound, which may be equal to one- 

(346) 



FEEDING GROWING ANIMALS 347 

fifth or more of the total dry substance of the ration for 
a very young animal. 

445. Food freely appropriated by growing animal. — 
More definite information is furnished by the somewhat 
limited studies which have been made of the metabolism 
of the calf. As long ago as 1878 Soxhlet studied the 
income and outgo of three young calves fed on whole 
milk. One pound of milk sohds, practically all digesti- 
ble, produced one pound increase of live weight, which 
was equivalent to a storage of at least one-third pound 
of body dry substance, a food efficiency for growth prac- 
tically ten times that exhibited with animals somewhat 
mature. Nearly 70 per cent of the protein of the food 
was fixed in the bodies of these calves and only a small 
proportion was broken down, conditions quite the reverse 
of those which pertain to the use of food by well-grown 
steers. Seventy-two per cent of the phosphoric acid and 
97 per cent of the lime were retained for the purposes of 
growth. Later experiments with calves fed on rations in 
whole or in part composed of skim-milk, show a deposit 
of from 26 to 43 per cent of the protein. These results 
illustrate the vigor with which a young animal assimi- 
lates food for growth. The facts show the necessity of 
feeding young animals on liberal quantities of constructive 
materials, viz., the proteins and ash ingredients. 

446. Influence of kind of food on the kind of growth. — 
During recent years there has been much discussion 
and many experiments touching the influence of food 
upon the development of the animal body. Several 
experimenters, notably Sanborn and Henry, in this 
country, have compared the growth of swine on rations 
presenting extreme differences, as, for instance, mid- 
dlings and blood against corn meal alone, or shorts and 



348 THE FEEDING OF ANIMALS 

bran against potatoes, tallow, and corn meal. As would 
be expected, the development of the two lots of pigs was 
in these cases greatly unlike. Those fed on the nitrog- 
enous rations contained more blood than the other; 
their organs, such as the kidneys and liver, were much 
larger in proportion to the weight of the body, the bones 
were stronger, and the proportion of muscle in the car- 
cass was much greater. The differences were very marked. 
It should not be forgotten, however, that these were 
extreme and somewhat unusual rations. It is doubtful 
whether there are generally sufficient differences in the 
food combinations of ordinary practice to occasion such 
marked differences of body structure. 

At the Cornell University Experiment Station lambs 
fed on oil meal and bran made a much more satisfac- 
tory gain than did those the grain ration of which was 
corn meal alone, but the photographs of the carcasses do 
not show a larger proportionate growth of muscular tissue 
from the nitrogenous foods. 

An elaborate study of the influence of the ration 
upon the composition of the carcass was made at the 
Maine Experiment Station, where two lots of steers 
were fed from calfhood on rations widely unlike in their 
nutritive ratio. The hay fed was the same for both lots. 
The grain food of one lot was oil meal, wheat bran, and 
corn meal, and of the other lot corn meal, mixed with a 
minimum proportion of wheat bran, the nutritive ratios 
being respectively 1 : 5.2 and 1 : 9.7. One animal from each 
lot was killed at the end of seventeen months of feeding 
and the others at the end of twenty-seven months, the 
entire bodies of the four steers, exclusive of the skins, 
being analyzed. It was found that the composition of 
the animals did not differ materially. (See Table LXXV.) 



FEEDING GROWING ANIMALS 



349 



Table LXXV. 



Percentage Composition of Total Dressed 

Carcasses of the Steers 





In fresh substance 


In water-free 
substance 








'v 
o 




T. 

< 


1 




< 






Per 


Per 


Per 


Per 


Per 


Per 


Per 


Protein, rich food — 




cent 


cent 


cent 


cent 


cent 


cent 


cent 


Steer No. 1 


17 


59.02 


17.89 


18.53 


4.56 


43.66 


45.23 


11.11 


Steer No. 2 


27 


51.91 


16.93 


25.86 


5.30 


35.20 


53.78 


11.02 


Protein, poor food — 


















Steer No. 3 


27 


52.16 


17.10 


25.32 


5.42 


35.75 


52.90 


11.35 


Steer No. -i 


17 


56.30 


17.82 


20.27 


5.61 


40.77 


46.39 


12.84 



The amount of growth was at first more rapid with 
the more nitrogenous ration, but the kind of growth 
appeared to have been controlled by the somewhat fixed 
constitutional habits of the breed. Nevertheless, the 
evidence of all well-conducted experiments and of all 
experience is unanimous in emphasizing the necessity of 
supplying in the food of young animals an abundance of 
those nutrients which are needed for the building of 
bone and muscle. A satisfactory development of the 
organism at maturity is insured only when the early 
growth is liberal and uniform, and is such as to produce 
strong bone and a vigorous muscular system. More 
than this, there is induced by proper nourishment a 
lively temperament of energy of body, which chemical 
analysis cannot search out or measure, but which gives 
the chief value to certain classes of animals and is desira- 
ble in all. It is believed that this condition of strong 
vitality is promoted by a liberal supply of the proteins 
in the food. 

447. Estimated energy requirements for one pound 
of gain in weight by growing cattle and sheep. — Armsby 



350 



THE FEEDING OF ANIMALS 



has made estimates of the requirements for each pound of 
growth of cattle and sheep at different ages, for which he 
does not claim any high degree of accuracy.* 



Table LXXVI 



Age 


Energy value 


Months 

3 


Therms 

1.5 


6 


1.7 


12 


2. 


18 


2.5 


24 


2.75 


30 


3. 







This would indicate that for an animal of the age of 
three months a pound of growth would require an addi- 
tion to the ration of two and one-fourth pounds of oats, 
and at the age of thirty months four and one-half pounds. 

The same author gives estimated requirements a 
day and head for growing cattle, these to include the 
maintenance requirement :* 





Table LXXVII 








Age 


Live 


Digestible 


Energy 




weight 


protein 


value 


Months 




Pounds 


Pounds 


Therms 


3 




275 


1.1 


5. 


6 




425 


1.3 


6. 


12 




650 


1.65 


7. 


18 




850 


1.7 


7.5 


24 




1,000 


1.75 


8. 


30 




1,100 


1.65 


8. 



In order to give concrete expression to the standard 
that applies to a growing animal one year old, weighing 
650 pounds, there has been calculated the necessary ration : 

* Based on true protein and production values. 



FEEDING GROWING ANIMALS 351 

Pounds 

Clover hay 10 

Wheat middlings 3 

Linseed meal 2 

448. Milk for young animals. — In considering the 
feeding of very young animals, we recognize the mother's 
milk as in general supplying the necessary nutrients in 
the best forms and proportions. It is true in the case of 
cows that the very rich milk of the butter breeds, when 
generously fed, often causes a serious disturbance of the 
calf's digestive organs, but the fact remains that casein, 
milk-fat, and milk-sugar are adapted through Nature's 
design to the digestive processes and the nutrition of 
young animals. Moreover, milk is rich in the mineral 
compounds needed for bone formation. When, there- 
fore, it becomes necessary or desirable to substitute other 
food for the mother's milk, it is essential not to act 
counter to physiological necessities and conditions. 

One fact of importance is that the very young ani- 
mal is somewhat undeveloped in its capacity to digest 
the starchy grains and similar substances, the secre- 
tions necessary for this purpose not yet being abundant. 
It follows, then, that the first substitute for whole milk 
should not consist largely of the insoluble carbohydrates. 
Again, the young animal's stomach is at first unfitted for 
receiving and utilizing bulky, fibrous food. Some time 
must elapse before the calf or colt can secure much 
nourishment from grass, hay, or like materials. 

THE FEEDING OF CALVES 

449. Skimmed milk as a substitute for whole milk 
in feeding calves. — ^The most successful way of feeding 



352 THE FEEDING OF ANIMALS 

calves to secure rapid growth, especially to produce veal 
of the highest quality, is to supply them with whole milk 
up to the limit of their capacity when this can be done with 
safety. Where they are to be raised for stock purposes, 
satisfactory growth may be maintained with the use of 
substitutes for whole milk, which is fortunate, because 
with the exception of the western plains, where cows are 
cheaply kept simply for breeding purposes, or where a 
breeder is selling his increase at fancy prices, the feeding 
of whole milk is not warranted by the value of the result- 
ing animal. 

For this reason most dairymen, particularly those 
who sell milk as such, kill the calves at the age of a few 
days, excepting, perhaps, during that portion of the year 
when veal sells at a very high price. On the other hand, 
many dairymen who have a supply of skimmed milk 
successfully feed this to growing calves, when it is desired 
to raise heifers or even steers. Experience has shown 
that it is entirely practical to do this, and it is certainly 
economical, for experiments have demonstrated that, as 
prices average, the cost of a poimd of growth so produced 
is at least not over one-third what it would be if whole 
milk were fed. 

As a guide in providing a substitute for whole milk, 
it may be stated that a vigorous calf should very early 
be made to eat daily not less than three pounds of highly 
digestible matter with a nutritive ratio at first not wider 
than that of whole milk solids. The exclusive feeding of 
skimmed milk for any length of time is not to be recom- 
mended. Experience shows that for young calves it 
should be so combined with other materials that a mix- 
ture is obtained which, so far as possible, resembles 
whole milk in its nutritive ratio. After the fat is removed 



FEEDING GROWING ANIMALS 353 

from the milk, the non-nitrogenous compounds are 
probably not present in sufficient proportion to protect 
the protein from waste as fuel. No feeding-stuff appears 
to be a more efficient amendment of skimmed milk for 
the earliest feeding than flaxseed meal cooked into a 
porridge. The explanation of this is the high percentage 
of oil in this meal, its low content of starch, and its high 
rate of digestibility. Besides, it appears to promote a 
healthy condition of the organs of digestion. Oil meal 
may be used in its stead, but it is less desirable at first. 
The calf should be allowed whole milk for a few 
days, not necessarily more than a w^eek, when it may 
be gradually changed over to skimmed milk and flax- 
seed meal. An admirable mixture is prepared by cook- 
ing the flaxseed meal in water in the proportion of one 
to six by volume, and adding a small amount of this 
(the equivalent of three or four tablespoonfuls of the 
dry meal at first) to eighteen or twenty pounds of warm 
skimmed milk, which may serve as a day's ration. The 
quantity of meal should be gradually increased up to one 
pound a day inside of a few weeks. In six or eight weeks 
the calf should be allowed access to dry oatmeal, or oat- 
meal and wheat middlings, or the oatmeal and middlings 
may be boiled with the flaxseed meal and mixed with the 
milk. After ninety days the flaxseed meal may be dropped 
for the sake of economy. The calf will soon appreciate 
a wisp of early cut hay, some coarse food becoming 
a necessity before many months pass. This method 
of feeding has repeatedly produced rapid growth and 
fine animals. For heifers it is probably to be preferred 
to whole-milk feeding, as it is fiilly as conducive to the 
vigorous development of the muscular system and is less 
likely, perhaps, to promote a tendency to lay on body fat. 
w 



354 THE FEEDING OF ANIMALS 

450. Calf rations without milk products. — ^An exam- 
ination of the results of much experimental work shows 
very clearly that strong, healthy calves can be raised 
without skimmed milk or even milk of any kind after a 
brief period, although the rate of gain may not be so 
rapid as when whole milk or skimmed milk is available 
for at least part of the ration. In these experiments, 
where careful records have been made, mixtiues of oat- 
meal and other cereal products with linseed meal, thor- 
oughly cooked, may be used to produce satisfactory 
growth, even if gro^i:h is not so rapid as with milk prod- 
ucts. This appears to be no disadvantage in the subse- 
quent development of the animal. Even if skimmed 
milk is available, cereal products and the oil-meal prod- 
ucts make desirable amendments to the milk. 

The Dairy Division of the United States Department 
of Agriculture, in experiments with twenty-two animals, 
has showed that calves make as rapid gain upon sour 
skimmed milk as upon sweet skimmed milk, other experi- 
ments indicating that whey may be used as a substitute for 
skimmed milk, provided proper foods are combined with it. 

Hay tea is sometimes used as a milk substitute, but 
it is a poor one. Only a small proportion of the nutrients 
of hay is soluble, and the water-extract is a dilute and 
comparatively innutritions food for a growing animal, 
the use of which can be justified only in the absence of 
milk in any form, and which, when used, must be very 
liberally fortified by grain feeds. 

THE FEEDING OF LAMBS 

451. Feeding ewes with lamb. — ^The first growth of 
lambs is chiefly from the mother's milk and we have little 



FEEDING GROWING ANIMALS 355 

occasion to consider substitutes for this food. The fact 
first in order and most important in this connection is 
that well-fed mothers are absolutely essential to rapid 
growth. A lamb must be fed through its dam. Nothing 
is more pitiable than the sight of a pair of himgry twin 
lambs making an effort to satisfy their insistent demands 
for growth with the milk furnished by a small, lean, 
under-fed mother. The treatment of the ewe before 
the birth of her young should be such as to prepare her 
for the strain of supplying a generous flow of milk. 

Ewes that are suckling lambs, while fed from the barn, 
should be supplied with good clover or alfalfa hay, or hay 
from fine mixed grasses. Pea and bean straws are excel- 
lent coarse feeds for sheep. Timothy hay is an abomina- 
tion as sheep food, especially under . these conditions. 
The grain ration should not be less than three-fourths 
of a pound daily, made up in part of one or more of the 
highly nitrogenous feeding-stuffs. It is also desirable to 
feed a small proportion of some succulent food. What is 
needed is a milk-producing ration, and the discussion of 
feeding cows for milk production in a preceding chapter 
is in part pertinent to ewes. Corn, oats, wheat bran or 
middlings, beans, peas, gluten and oil meals are all useful 
in making up such a ration. With safe feeding, one pound 
daily of a mixture of oil or gluten meal one part, wheat 
bran two parts, and corn meal two parts, combined with 
two or three pounds of roots or silage and what coarse 
feed the appetitite will bear, is a good milk ration, and 
will bring the ewes through the strain of suckling lambs 
in good condition. 

452. Grain foods accessible to lambs. — ^If it is desired 
to produce the most rapid gro^\i-,h of the lambs, they 
should also have access from nearly the first to a grain 



356 THE FEEDING OF ANIMALS 

mixture. Experiments indicate that this mixtm^e is most 
economical, especially if the lambs are to be fed later for 
the market, when containing a generous proportion of 
corn meal, to which may be added, among other mate- 
rials, ground oats, wheat bran, gluten feed or meal, or oil 
meal, reference being had to the ruling market prices. 
In an experiment at the Maine Experiment Station, 
lambs suckled by grain-fed mothers and with access to 
grain themselves made 75 per cent or more gain in live 
weight than those did that received no grain and which 
were suckled by mothers that ate a limited grain ration. 
Five and three-fourths pounds of grain produced one 
pound of growth. At the Wisconsin Experiment Station, 
as an average of three trials, lambs fed grain before wean- 
ing gained in ten to twelve weeks seven and a half 
pounds more each than those not so fed. Four pounds 
of grain produced one pound of live weight. 

Liberal feeding means more economical growth, a 
higher quality of product, and the earliest possible mar- 
ket. The foregoing discussion is applicable to the rais- 
ing of early lambs. If, however, they are dropped dur- 
ing the grazing season where the ewes have abundant 
pasturage, the question of feeding is simplified, for no 
ration is more promotive of abundant milk secretion 
than young grass; besides, the low price at which late 
lambs are usually sold does not encourage extensive grain 
feeding. When lambs are grown for breeding stock their 
early grain rations should be lighter, and may properly 
consist more largely of oats and bran, with a smaller 
proportion of corn. 

453. Standards for growing sheep. — For growing 
sheep beyond the age of six months, Armsby has offered the. 
following standards, based on Kellner's production values: 



FEEDING GROWING ANIMALS 



357 



Table LXXVIII. Estimated Requieements per Day and 
Head for Growing Sheep 



Age 


Live weight 


Digestible 
protein 


Energy 
value 


Months 

6 

9 

12 

15 

18 


Pounds 

70 

90 

110 

130 

145 


Povmds 

.30 
.25 
.23 
.23 
.22 


Therms 

1.30 
1.40 
1.40 
1.50 
1.60 



Expressed in terms of an actual ration a bunch of ten 
growing lambs nine months old would require on the 
basis of the foregoing standard the following quantities: 

Ration for Ten Lambs, 900 Pounds. Age Nine Months 

Pounds 

Clover hay 20 

Turnips 20 

Peas 4 

Linseed meal 2^ 



FEEDING COLTS 

454. Food as related to quality of the horse.-:— The 
value of a horse for either draft or road purposes is greatly 
dependent upon those physical qualities which secure 
vigor and endurance. A horse is not regarded as desira- 
ble that is devoid of "nerve" and that cannot sustain, 
if necessary, the strain of hard, or even severe, work; 
and breeders seek to produce animals having these char- 
acteristics. Two main factors are involved in the proper 
physical development of the colt: food and exercise. The 
latter is a part of the general management to which the 
horse-breeder must give detailed attention and will not 
be discussed in this connection. The technics with which 



358 THE FEEDING OF ANIMALS 

the horseman should be famihar must be learned through 
experience and by consulting special literature. 

It is proper to state that our knowledge concerning 
the feeding of colts consists largely of the conclusions 
derived from experience of practical men. Very little 
experimental attention has been given to this subject 
by investigators. During the years that experiment 
stations have existed in the United States few stations 
have reported experiments along this line, and these were 
not extensive; but notwithstanding the lack of direct 
data from scientific sources there are well-proven and 
safe facts to which we can refer. 

455. Feeding the colt through the dam. — ^The proper 
feeding of the young foal is accomplished first through 
the proper feeding of the dam. The mare with a colt at 
her side should be regarded as a milch animal, making 
demands upon the food for generous milk production 
similar to those made by the milch cow. This is equiva- 
lent to the statement that when suckling her foal the dam 
should be given foods that stimulate milk secretion. If 
she is allowed the run of a good pasture, both mother and 
colt will usually thrive satisfactorily. Young pasture 
grass is as efficient with the mare as with the cow. If, on 
the other hand, the feeding is from the stable, either 
wholly or to amend an insufficient or inferior food-supply 
from grazing, then the grain ration should be made to 
include such feeding-stuffs as barley, oats, wheat, wheat 
bran, wheat middlings, peas, and even a small propor- 
tion of linseed meal. Whenever soiling-crops are grown 
these may be fed, especially alfalfa. In case the legume 
fodders are available, either green or dried, the necessity 
for protein in the grain is not so great and corn may 
form a larger proportion of the ration. 



FEEDING GROWING ANIMALS 359 

A good grain mixture for ordinary conditions would 
be cracked corn two parts, wheat bran seven parts, and 
linseed meal one part; or ground oats four parts, wheat 
middlings five parts, and linseed meal one part. 

456. Rations for the colt before weaning. — Before the 
colt is weaned, with good management, he will learn to 
eat grain which is very likely to be the same mixture as 
that eaten by the dam. If desired, an enclosure may be 
built, into which the colt and not the mother can pass, 
where a special grain food may be provided. This brings 
us to the consideration of what shall be the grain ration 
of the colt, both before and after weaning. 

457. Oats as horse feed. — ^The opinion is generally 
held that oats are superior to all other feeding-stuffs as 
horse food, particularly for the development of those 
qualities of temperament and muscle which are regarded 
as so desirable, especially in a carriage horse. Oats are 
usually comparatively costly, but it is claimed that the 
superior results, whether in the kind of development of 
the colt or in the quality of service of the mature animal, 
justify their use. In this particular case, as in others, 
certain statements are cin-rently accepted as facts which 
have no well-established basis. 

Reference is frequently made to the tonic effect of 
oats, and there has existed a popular notion that this 
grain contains a peculiar compound which acts as a nerve 
stimulant and imparts "life" to the horse. 

It was announced in 1883 that Sanson had discovered 
in oats a characteristic alkaloid having a stimulating 
effect upon the motor nerves of the horse, but subse- 
quent elaborate investigations by Wrampelmyer failed to 
verify Sanson's conclusions. Notwithstanding the fact 
that the oat kernel has been the subject of very care- 



360 THE FEEDING OF ANIMALS 

fill chemical studies, it is not found that it contains any 
compounds so characteristically unlike those of other 
grains as to account for an unusual influence upon the 
nervous system, or for a superior development of the 
muscles. 

It may be suggested that the "life," or nervous con- 
dition, of a horse is a resultant of several factors or 
influences. These are the quantity of digestible food sup- 
plied, the proportion of protein in the ration, the con- 
dition of the digestive tract, care, exercise, and all the 
many small influences which affect health. In those 
instances where feeding oats has seemed to improve the 
performance of the horse, even if this has actually 
occurred, we have no assurance that in changing the 
ration the amount and proportions of the nutrients 
digested have remained the same. It seems entirely 
probable that if thorough comparison could be made 
between oats and the best grain mixtm^es which could 
be suggested in the light of present knowledge, the oats 
would not maintain so great a superiority over other 
feeds for growing colts as is now generally attributed to 
them. Experiments which have been made indicate that 
for producing rapid growth oats were inferior to either a 
mixture of peas and middlings, or to a mixture of mid- 
dlings, gluten meal, and linseed meal; but these obser- 
vations were not carried far enough to determine the 
relative effect upon the quality of the animal. 

458. Rations for growing colts. — Doubtless all neces- 
sary conditions for producing growth and quality in colts 
can be met by a ration of which oats form a part. The 
following grain mixtures are suggested as illustrative of 
good ones: 



FEEDING GROWING ANIMALS 361 

Mixture 1 Mixture 2 

Parts Parts 

Oats 4 Corn 2 

Bran or middlings ... 4 Oats 4 

Peas 2 Bran 3 

Oil meal 1 - 

These mixtures are generally less expensive than oats 
alone, and in kind fully meet the demands for growth 
of both bone and muscle. 

Henry gives as a fair allowance of grain for a colt, 
measured in oats, the following quantities: Up to one 
year of age, two to three pounds; from one to two years, 
four to ^Ye pounds; from two to three years, seven to 
eight pounds. In using the other grain feeds suggested, 
which mostly have a higher rate of digestibility than oats, 
no larger quantities would be necessary. Skim-milk may 
be fed to colts in limited amounts with good results, as 
experiments show. Feeding it in quantities sufficient to 
force very rapid growth is not wise. 

It is generally conceded that the colt should be allowed 
to eat a reasonable proportion of coarse feed as a means of 
properly developing the digestive tract. It is entirely pos- 
sible to supply concentrated grains too freely, to the 
exclusion of more bulky materials, and in that way fail 
to secure a desirable distension of the alimentary canal. 
This does not mean that the colt should be allowed to 
gorge himself w^ith hay or other coarse material, as an 
unfortunate extreme in this direction is easily reached. 



CHAPTER XXI 

FEEDING ANIMALS FOR THE PRODUCTION OF 

MEAT 

The production of beef was at one time a source 
of income to nearly all farms. In earlier days the New 
England farmer annually sent to the market a few fat 
steers or oxen. The beef consumed in the United States 
and that exported now comes very largely from the wide 
grazing areas of the West, where the cost of feed and the 
necessary amoimt of labor are at a minimum. The 
reasons for this change are not hard to find. The food 
cost of beef-making is relatively large as compared with 
dairy products, and in the East the growth of home 
markets for milk and cream has made it possible for 
farmers to turn their high-cost feeding-stuff into prod- 
ucts having a higher proportionate market price than 
beef. Moreover, certain eastern lands have, with enlarg- 
ing markets, been occupied to good advantage with fruit 
and vegetables. The time has come, now that the wide 
areas of the West are more densely peopled, when beef 
production is receiving more attention in the eastern 
states. Some eastern farmers appear now to find it profita- 
ble. It is certain that it involves good judgment, skill, 
and the art of feeding to the highest degree, especially if 
fair returns are to be secured. The breeding or selection 
of animals of the most profitable type that will supply 
the market with a high-grade product, and stable feed- 
ing, so as to produce rapid and continuous increase, 

(362) 



FEEDING FOR MEAT 



363 



requires experience and an intelligent application of all 
the factors involved. 



BEEF PKODUCTION 



459. Nature of the growth with beef production. — 

Feeding steers or oxen for the market may be carried 
on with yomig animals that are still making some growth 
of bone and muscle, or with those so mature that addi- 
tional weight comes almost wholly from a deposition of 
fat in the tissues already formed. This is the difference 
between feeding a two-year-old and a five-year-old steer. 
In either case the predominating constituent of the 
increase is fat. This fact is established by the investi- 
gation of Lawes and Gilbert and by one experiment in 
this country. Gilbert, in his lectures summarizing the 
Rothamsted work, gave the following figures: 



Table LXXIX. 



Composition of Increase When Steers Are 
Fattening 



Oxen fattened very young 

Matured animals, final period .... 

American results with well-fed steers, 
growth from 17 months to 27 months 
of age 



Water 



Per cent 

32-37 
25-30 



42.4 



Ash 
Per cent 

IH 



Protein 



Per cent 

10 

7-8 



14.1 



Fat 



Percent 

50-55 
60-65 



37.5 



These figures may be regarded as reliable, and they 
show most conclusively that in beef production the 
constructive use of the food is largely in the direction 
of fat-forming. 

460. Rate of increase of fattening animals. — The 
extent of the actual production which occurs can be 



364 THE FEEDING OF ANIMALS 

closely estimated for any given case. It is considered 
satisfactory if the rate of increase during a reasonably 
long period of fattening is 2 pounds live weight a day. 
This means the actual addition to the dry substance of 
the body of from 1.3 to 1.5 pounds. Sometimes during 
short periods with excessive feeding the daily gain may 
be 3 pounds live weight, and generally after animals are 
well fattened, during the finishing period, it may be as 
low as 1 pound or less. The actual daily growth of new 
material may vary then, aside from the water, from .6 to 
2.25 pounds a day. Actual fat formation may thus 
range from .4 to 1.8 pounds a day. The protein-con- 
tent of the increase, on the other hand, probably does 
not exceed .3 pound daily in any instance, and with 
mature animals it is very insignificant. 

461. The food needs of the fattening steer. — In view 
of the foregoing facts and of the conclusion as to the fat- 
forming function of carbohydrates, it is clear that the 
non-protein part of the ration may be the source of the 
chief part of the body substance laid on by a fattening 
steer. The amount of protein necessary for constructive 
work seems to be very small — with mature animals it is 
practically nothing. It would seem, then, looking at the 
matter merely from the standpoint of the demands for 
growth, that in feeding fairly mature animals for beef 
production a ration may be efiicient with a wide nutritive 
ratio, much wider than was recommended in the Ger- 
man standards. 

It is recognized, though, that we cannot decide upon 
a ration merely upon the basis of the raw materials that 
are needed for constructive purposes. The influence of a 
particular feed or of a variety of feeds on the appetite 
and on what we speak of as general condition, as 



FEEDING FOB MEAT 365 

well as upon the quality of the product, and the necessity 
of avoiding so large a preponderance of carbohydrates 
as to cause a possible depression of digestibility, are all 
points which must be considered in determining the value 
of a ration. We should remember, also, that the stimulat- 
ing effect of the food upon the vital functions is a factor 
in successful feeding. So, after all, we must appeal tc 
experience, scientific and practical, for information as to 
what rations are efiicient for fattening purposes. 

The German standard rations for fattening bovines 
which were recommended called for 18 to 18.4 pounds of 
digestible organic matter daily for each 1,000 pounds of 
live weight, with a ratio of 1 : 5.4 to 1 : 6.5, requiring from 
2.5 to 3 pounds of a digestible protein. In view of more 
recent scientific conclusions concerning the functions of 
nutrients, it is not easy to understand why a fattening 
steer requires more protein than a milch cow or even 
as much. 

462. Scientific experiments with fattening animals. — 
Feeding experiments w^ith fattening oxen, conducted 
under the improved methods of research, give results 
not inconsistent with the facts to which attention has 
been called. Kellner made a large number of experi- 
ments with fattening animals by the aid of the respiration 
apparatus, and he concluded that the nutritive ratio of 
a fattening-ration may vary from 1:4 to 1 : 10 without 
affecting the increase of body substance from a unit of 
digestible food material, provided, however, that the 
nutrients supplied above maintenance needs shall come 
from the more easily digestible feeding-stuffs. He cites, 
in the support of his conclusion, the outcome of nineteen 
previous experiments by Wolff, in which rations varying 
in nutritive ratio from 1:4 to 1 : 9.5 showed no material 



366 THE FEEDING OF ANIMALS 

differences in the efficiency of a unit of digestible matter. 
It seems to be agreed that a wide nutritive ratio is not 
inconsistent with most successful feeding of fattening 
steers, especially those that are mature. If the animals 
are so young as to be making material growth, there is 
more reason for avoiding a very wude ratio. 

463. Practical feeding experiments in fattening ani- 
mals. — ^Among the practical feeding experiments con- 
ducted in the United States, there are several instances 
w^here the wide-ratio rations have been found equal to 
the more nitrogenous. On the other hand, and perhaps 
in a majority of experiments, the rations containing the 
largest proportion of protein have caused the most rapid 
growth. In 1893 the writer made a careful study of many 
previous experiments and found that the addition of some 
highly nitrogenous feeding-stuff to corn meal, or other 
home-raised grain, in most instances increased the pro- 
ductive value of the ration. This fact stands in apparent 
conflict with the more scientific conclusions to which 
reference has been made. The probable explanation of 
this discrepancy is that the rations richest in protein 
have generally contained the greater variety of feeding- 
stuffs, have been more palatable, more stimulating to 
the appetite, and, in general, have caused a more vigorous 
exercise of the animal's functions. The proportion of 
protein has probably been a minor factor. If as great a 
variety of as palatable and as easily digestible materials 
can be fed without the use of highly nitrogenous feeding- 
stuffs as with them, the result will doubtless be just as 
favorable. This means that a mixture of home-raised 
grains may form as efficient a ration for fairly mature 
fattening steers as when the oil meals or gluten meals 
are introduced. Palatableness, variety, and ease of 



FEEDING FOR MEAT 367 

digestion are the main points to be secured, and these 
factors have been somewhat overshadowed by the effort 
to secure merely a definite nutritive ratio. 

It need not be feared that when mixed cereal grains 
are fed as the major part of the ration, there will be 
a materially lower rate of digestibility than when a 
protein food is introduced. There is still something to 
be said, however, in favor of adding to a fattening-ration 
a small proportion of an oil meal, or of some material 
of similar character, for palatableness is thus promoted, 
and observations show, in many instances, that an 
appearance of greater thrift and vigor is thus induced, 
which is perhaps due to the stimulating effect of the 
greater amount of circulatory protein upon the metabolic 
processes of the animal. With young steers making some 
growth of bone and muscle, a small quantity of a protein 
food is of unquestioned advantage. 

464. German fattening for bovines' ration excessive. — 
The German standard for fattening cattle is open to 
criticism as to the quantity of nutrients recommended 
for 1,000 pounds of live weight. In order to supply 18.4 
pounds of digestible organic matter it would be neces- 
sary to feed, for instance, 8 pounds of hay and 21.5 pounds 
of an ordinary mixture of corn meal, bran, and oil meal. 
While it may be possible to induce young steers weigh- 
ing from 600 to 800 pounds to eat at this rate for a short 
time, so large a ration is seldom, if ever, so profitable as 
a smaller one, even if it could be fed w^ith safety. If an 
attempt were made, how^ever, to apply this formula to 
mature steers weighing from 1,300 to 1,500 pounds the 
situation would become absurd, because the ration would 
then be from 10.5 to 12 pounds of hay and from 25 to 32 
pounds of mixed grains for a single animal. An appeal 



368 



THE FEEDING OF ANIMALS 



to concrete examples of steer-feeding will clearly show 
the excessive requirements of the German standard for 
fattening cattle. In 1891 to 1893 the Kansas Agricul- 
tural Experiment Station conducted feeding experiments 
with three-year-old steers, and as these are good exam- 
ples of practical management, the data from them will 
serve to illustrate the point under discussion. These 
data are stated in a tabular form : 



Table LXXX 

First Second 

experiment experiment 

Number of animala 5 3 

Days fed 182 129 

Poiinds Pounds 

Weight per animal, average for period 1,412 1,237 

Hay eaten per day 7.8 6.7 

Grain eaten per day 23.9 23. 

Daily gain per animal 2.39 2.4 

Digestible organic matter daily per animal 19.5 19. 

Digestible organic matter per 1,000 pounds live weight . . 13.8 15.3 

In 1895-1896 the Iowa Agricultural College fed steer 
calves for fourteen months, during ten of which a record 
was kept of all the food consumed. During the second 
period the steers were fattened for market. This particu- 
lar experiment is cited because the animals were young 
and all the conditions were favorable to the maximum 
consumption of food in proportion to live weight: 

Table LXXXI 

First Second 

period period 

Number of animals 5 5 

Days fed 120 181 

h.ge of steers at beginning 9 to 10 mos. 16 to 17 mos. 

Pounds Pounds 

Weight per animal, average for period 766 1,197 

Coarse food eaten daily (partly roots and green fodder J 11 12.8 

Grain eaten daily (partly snapped corn) 9 19.5 

Daily gain per animal 2.04 2.11 

Gain per 1,000 pounds live weight 2.66 1.76 

Digestible organic matter daily per animal ... 10. 14.1 
Digestible organic matter daily per 1,000 pounds live 

weight 13. 11.8 



FEEDING FOR MEAT 369 

The largest amount of digestible nutrients fed daily 
to each animal at any time during this experiment was 
about 17.5 pounds, after the animals had reached an 
average weight of 1,200 pounds or over. This would be 
approximately 14.5 pounds digestible organic matter 
for each 1,000 pounds Hve weight. 

These two experiments are instances of successful 
feeding where the increase w^as rapid and very satis- 
factory and where the quantity of digestible nutrients 
supplied daily w^as greatly below 18 pounds for each 1,000 
pounds live weight. 

It is concluded, from observation and a study of the 
results of experiments, that under proper conditions 8 
to 10 pounds of dry coarse food and 15 to 18 pounds of 
grain is all that can generally be fed with greatest profit 
to a steer actually weighing 1,000 pounds, and may be 
even more than is utilized by the animal to the best 
advantage. Such a ration would supply about 16 pounds 
of digestible organic matter. If considerably smaller 
steers are fed, the ratio of food to weight may be increased, 
but if the animals are several hundred pounds heavier 
the ratio may be materially diminished. It is safe to 
accept as a general principle the rule that the larger the 
animal the less the proportion of food to weight. The 
fixing of the quantity of a fattening-ration directly in 
proportion to the size of the animal is a simple and quite 
convenient rule, but is utterly impracticable and is so 
recognized at present in the standards for growing ani- 
mals, and should be in all estimates and proportions. 

465. The selection of a fattening-ration. — ^Two con- 
ditions already mentioned that are of the highest impor- 
tance should not be forgotten, viz., that the ration should 
be palatable and be composed of a variety of easily diges- 

X 



370 THE FEEDING OF ANIMALS 

tible materials. Rough fodder in any quantity is not 
adapted to fattening bo vines. With this exception, the 
whole list of high-class cattle foods may be regarded as 
available, and the selection will properly depend largely 
upon prices and the local supply. In the northern states, 
hays from the fine grasses and the legumes, silage, roots, 
cereal grain mixtures, and such by-product feeding-stu£Fs 
as offer digestible nutrients at the least cost will all 
appeal to the experienced feeder. In the South, cotton- 
seed by-products may, with economy, enter largely into 
the ration. In the West, the fodders peculiar to that 
region will be utilized, corn being the chief, and some- 
times the only, grain that can be fed with economy. 

466. Suggested rations for fattening steers. — ^The 
following may be regarded as good types of mixtures 
for the full feeding of fattening steers weighing approxi- 
mately 1,000 pounds each at the beginning of the feed- 
ing period. They will supply about 16 pounds of digesti- 
ble organic matter if their components are of average 
quality and composition: 

5 lbs. clover hay. / 5 lbs. clover hay. 

16 lbs. com silage. k)^^ ^^®' ^^^^ pulp. 
13 lbs. corn meal. j 11 lbs. com meal. 

3 lbs. wheat bran. \ 2 lbs. cottonseed meal. 

10 lbs. com stover. / 8 lbs. com stover. 

• 20 lbs. mangels. 6< 12.5 lbs. com meal. 



)^12.^ 
(20 ] 



3 



14.5 lbs. com meal. (20 lbs. brewers' grains, wet. 
2 lbs. cottonseed meal. 

8 lbs. mixed hay. { 2 lbs. oat straw. 

12.5 lbs. com meal. '7)'^^ ^hs. beet pulp. 



3 lbs. wheat bran. j 10 lbs. beet molasses. 

2 lbs. oil meal or gluten feed. ' 4 lbs. gluten meal. 
/ 8 lbs. alfalfa hay. { 5 lbs. alfalfa hay. 

4< 12 lbs. corn meal. ^^l 3 lbs. corn stover. 

\ 5 lbs. ground oats. J 11 lbs. com meal. 

\ 6 lbs. ground barley. 



FEEDING FOR MEAT 371 

The above rations are well up to the quantity limit 
for the profitable feeding of animals weighing approxi- 
mately 1,000 pounds. They are simply illustrative, how- 
ever, both in kind and in quantity. Many mixtures 
equally efficient may be used, and the quantity of the 
ration must vary not only with the age and size of the 
animal but with individuals, according to appetite 
and capacity. Any feeder of experience will understand, 
of course, that such rations will be eaten with safety to 
the animal only after a period of preliminary feeding, 
during which there has been a gradual increase in the 
quantity of food offered. 

MUTTON PRODUCTION 

Attention has been called to the fact that beef pro- 
duction in the United States has gravitated to the ex- 
treme West. This is also true of the production of mutton 
though not to the same extent. Flocks of sheep are still 
kept on many farms of the eastern and middle West 
states, and the growth of early lambs and the fattening 
of maturer animals to supply the demands of the local 
markets is found to be most profitable by those farmers 
who possess the knowledge and skill requisite for this 
branch of stock husbandry. 

467. Place of sheep on the farm. — Sheep occupy a 
peculiar place on the farm in that they will accommodate 
themselves to pasturage that is not adapted to cows and 
horses, and will utilize some kinds of rough fodder not 
readily eaten by other farm animals without submitting 
it to somewhat expensive methods of preparation. If it 
were not for the discouragement which sheep husbandry 
has received from the depredations of dogs, sometimes 



372 THE FEEDING OF ANIMALS 

real and sometimes greatly overestimated or even 
imagined, the production of wool and mutton would 
greatly increase on the hill farms of this country, with 
undoubted profit to eastern agriculture, especially where 
soil fertility needs strengthening in every possible 

way. 

468. The nature and extent of the growth in fatten- 
ing sheep. — ^The character of the animal that is fattened 
for mutton varies within wider extremes than in steer- 
feeding. This is due chiefly to the greater range in ma- 
turity of the former, from the two months' lamb to the 
mature wether. There are corresponding differences in 
the nature of the increase while fattening, according as 
the animal is young and making growth of all parts of the 
body, or is simply storing fat in the mature organism. 
The character of the body substance stored, probably, is 
also influenced by the stage m the fattening period, 
whether at the beginning when the animal is thin or near 
the end when a fat sheep is becoming fatter. The only 
definite data which can be presented relative to the com- 
position of the increase of fattening sheep are based upon 
the analyses by Lawes and Gilbert of animals in various 
states of fatness. These investigators analyzed a "store" 
sheep, a "fat" sheep, and a "very fat" sheep, and from 
the figures thus obtained is calculated the increase in two 
stages of fattening: 

Table LXXXII. Composition of Increase of Fattening Sheep 

Dry 
substance Ash Protein Fat 

Percent Percent Percent Percent 

Increase from "store" to "fat" 

condition 78. 2.12 7.16 68.8 

Increase from "fat" to "very fat" 

condition 81-8 3.12 7.75 70.9 



FEEDING FOR MEAT 373 

A comparison with the increase of fattening oxen 
shows that the sheep stores the larger proportion of fat 
in the dry substance laid on. 

Sheep liberally fed give a larger increase to the 1,000 
pounds live weight than steers. With animals weighing 
from 75 to 150 pounds each, the daily gain with good 
management may range from .2 to .5 pound a head, or 
from 2 to 5 pounds to the 1,000 pounds, live weight, the 
increase varying according to age, conditions, and liber- 
ality of feeding. Lambs will sometimes greatly exceed 
the above maximum. If we base our estimates upon what 
will occur with the maturer animals, a number of lambs 
or sheep weighing 1,000 pounds, perhaps seven, perhaps 
twice as many, will store daily .15 to .40 pound of pro- 
tein and from 1.4 to 3.5 pounds of fat. 

469. Food needs of fattening sheep. — ^After long-con- 
tinued and careful experiments in feeding a fattening- 
ration to mature sheep, whose composition was investi- 
gated at various stages of fatness, Henneberg concludes 
that the very small amount of protein tissue laid on by 
such animals may be ignored. Pfeiffer reached the same 
conclusion from experiments with the same class of 
animals. This view would not hold with lambs during 
their increase from weaning time to one hundred pounds 
in weight, for in this period there must be a material and 
continuous storage of nitrogenous tissue. 

As is the case with steers, the demand for protein 
storage is seen to be small with mature fattening sheep, 
the constructive use of the ration being largely directed 
to fat formation. The more recent views of the func- 
tion of the nutrients allow us to believe that, as with 
bovines, carbohydrates and perhaps fats play a leading 
part in supplying raw materials for the carcass increase. 



374: THE FEEDING OF ANIMALS 

There is one point of difference between steers and sheep, 
however, viz., the growth of wool with the latter, that 
requires the use of more or less food protein. 

The German standard for fattening sheep is 18.5 to 
18.6 pounds of total digestible organic matter for each 
1,000 pounds live weight, 3 to 3.5 pounds of which shall 
be protein, thus giving a nutritive ratio ranging from 
1 : 4.5 to 1 : 5.4. There is little doubt that this standard 
calls for an imnecessarily large proportion of protein. 
Neither scientific facts nor the observations of practice 
justify the conclusion that sheep will fatten faster when 
protein is so liberally supplied than when properly com- 
pounded rations with a wider nutritive ratio are fed. 
Doubtless more regard should be paid to the protein- 
supply with sheep than with steers, but it is difficult to 
adduce a single argument for insisting upon so narrow a 
nutritive ratio with any species of fattening animal, 
unless it becomes incidental to an economical purchase 
of feeding-stuffs. We may safely conclude that the 
resources of the farm are sufficient to supply enough 
protein for a ration of an efficient character for the class 
of animals under consideration, though we shoidd give 
due recognition to the fact that, with fattening lambs 
especially, the protein feeding-stuffs may be most effi- 
ciently utilized. 

470. Quantity of nutrients for fattening sheep. — ^The 
quantity of nutrients prescribed by the published stan- 
dard for fattening is practically the same for each unit of 
weight as that given for fattening bo vines. This runs 
contrary to common observation and the results of 
experiments. The standard for steers has been charac- 
terized as excessive, but this fault cannot be charged to 
the one for sheep, for, if anything, it is below the demands 



FEEDING FOR MEAT 375 

of practice. Even mature sheep about average size will 
consume 18.5 pounds of digestible nutrients for 1,000 
pounds live weight, but this ratio does not meet the 
requirements for the prevalent intensive feeding of lambs 
and yearlings weighing from 75 to 125 pounds each. It 
is easily demonstrable not only that sheep will utilize a 
proportionately larger quantity of food than bovines, but 
that they will make a relatively greater increase. The 
results of two experiments in fattening wether lambs, 
reported from the Iowa Agricultural College in 1896 and 
1897, when compared with the outcome of steer-feeding 
trials, serve admirably to illustrate the correctness of this 
statement. The lambs were divided among seven mutton 
breeds. Sixty-nine were fed 90 days and 64 others were 
fed 107 days. 

The main facts derived from these feeding trials are 
as follows: 

Table LXXXIII 

Number of animals 133. 

Average days fed 98.2 

Pounds 

Total average weight of animals 16,400 

Average weight single animal #123 

Dry matter consumed 51,000 

Digestible organic matter consumed 34,500 

Dry matter eaten daily per 1,000 pounds live weight 31.8 
Digestible organic matter eaten daily per 1,000 

pounds live weight 21.5 

Daily gain per 1,000 pounds live weight 3.73 

Daily gain per animal .467 

The food consumption in this instance of the suc- 
cessful fattening of lambs is considerably in excess of 
the German standard, and the amount of food consumed 
is not unusual, though it is stated that in the latter 
stages of the experiments the animals were crowded to 
their full capacity. 



376 THE FEEDING OF ANIMALS 

If a comparison is made of this experiment with the 
steer-feeding experiments previously cited it becomes 
clearly evident that the published feeding standards 
are not consistent in calling for practically the same 
quantity of nutrients for the same live weight of the two 
species. Sheep will consume at least one-quarter more 
food than steers and lay on flesh proportionately faster. 
Moreover, sheep appear to make a larger gain in live 
weight than steers for each unit of nutrients consumed. 
It may be that the testimony of the experiments cited 
relative to the points under discussion is not a correct 
expression of average conditions, but the differences shown 
are too marked to be accounted for by any unusual con- 
ditions pertaining to these feeding trials, and therefore 
indicate what may generally be expected in practice. 

471. The selection of a ration for sheep. — ^The range 
of feeding-stuffs from which a sheep ration may be 
selected is wide and includes practically all home-raised 
fodders and grains and the w^hole list of by-products. It 
cannot be said, though, that all materials are equally 
desirable as sheep food. Of the fodders, those from the 
legumes are especially to be sought, even pea and bean 
straws, and among the grains corn stands preeminent 
as the basis of a fattening-ration. Probably no feeding- 
stuffs are more favored for mixing with corn than oats, 
bran, and linseed meal, probably because none are more 
successfully used. Barley, peas, beans, gluten feed, 
gluten meal, and cottonseed meal have also been success- 
fully fed to sheep. A mixed grain ration is unquestion- 
ably to be preferred to any single grain or by-product, 
because with the mixture greater palatableness is insured, 
it is possible to maintain the consumption of a larger 
ration, and the danger to health of heavy feeding is less. 



FEEDING FOR MEAT 377 

The selection of the components of the grain mixture 
should be governed somewhat by market prices. A supply 
of silage or roots is much to be desired as a part of a sheep- 
fattening ration, especially when heavy grain rations are 
to be fed during a long period, although successful feeding 
during a limited time is entirely possible without these. 
A succulent food promotes appetite and health, however, 
and is usually economical and sometimes necessary. 

Rations made up in definite quantities will not be 
presented in this connection. The quantity of nutri- 
ents which it is desirable to supply is so variable accord- 
ing to the age and maturity of the animals to be fat- 
tened that a feeding standard is applicable to only one 
set of conditions not long maintained and therefore it 
must be freely and frequently modified according to the 
judgment of the feeder. It is, nevertheless, possible to 
offer practical suggestion as to the proportions of grains 
in the mixtures that will be found acceptable, and as to 
the kinds and quantities of coarse foods ordinarily utilized. 

In the Iowa experiments cited in this connection the 
grains used were corn, oats, bran, and linseed meal. In 
the last of these trials the grain ration for fifteen days at 
first was made up of corn, oats, and bran in the propor- 
tions 2, 2, and L When the feeding was well estabhshed 
the grains were oats, corn, bran, and oil meal, the rela- 
tion in quantity being 8, 8, 2, and 1 respectively. Each 
animal ate about one pound of roots daily and about 
two-thirds as much hay as grain. The lambs were fed 
up to the full ration very gradually, several weeks being 
occupied in doing this. For such preparatory feeding 
bran and oats are especially useful. When these tests 
began, each animal ate from one and a half to two pounds 
of grain daily, which quantity was increased later to 



378 THE FEEDING OF ANIMALS 

three pounds with the largest eaters, some individuals 
not taking over two. The conduct of these feeding trials 
typifies good practice, both as to materials and manage- 
ment, and may serve as a guide in handling other simi- 
lar feeding-stuffs. 

It is undoubtedly possible to feed sheep with equal 
success without the use of purchased grains, especially 
on farms where clover or alfalfa, roots, corn, oats, or 
oats and peas, are produced. We are not justified by 
experimental results in concluding that bran and oil 
meal or any other by-product feeds are essential to the 
highest success in fattening sheep, although these feeding- 
stuffs are very useful for this purpose. A mixed grain 
ration is always better than any single grain fed alone. 

Instances are on record of a successful combination 
of green forage crops with grain in fattening sheep. The 
legume fodders and rape may be fed profitably in the 
green state with the usual grain mixtures, care being 
taken to avoid indigestion from excessive eating of the 
green material. Grain in connection with ordinary pas- 
turage is a successful method of fattening sheep or lambs 
for the fall market. 

PORK PRODUCTION 

The feeding of swine is a matter of almost univer- 
sal interest to farmers. Even m the older portions of 
the East a few animals of this class are kept on nearly 
every farm. Swine are well adapted to the disposal of 
certain wastes, particularly those from the table and the 
dairy. They are especially useful as a means of profitably 
converting dairy by-products into a marketable form, and, 
moreover, during the past twenty-five years pork produc- 



FEEDING FOR MEAT 379 

tion has offered more encouraging inducements to the 
home consumption of grain than has beef production. 

472. Changes in pork production. — Within recent 
years there has been a great change in the methods of 
pig-feeding and in the character of the animal when 
placed upon the market. This is emphatically true of 
the eastern and middle states, where pork is grown wholly 
for local consumption. Formerly good feeders were not 
supposed to slaughter a pig under 300 pounds carcass 
weight, and many animals dressed 400 pounds when 
taken to the market, this size being secured only after a 
feeding period of twelve to eighteen months. Pork of this 
character was regarded as well adapted to packing. At 
the present time the demand of the local markets is for 
small carcasses weighing not over 150 pounds, and sup- 
plying the maximum proportion of lean cuts. This change 
is in the direction of greater profits for the farmer because 
the food expenditure required for the production of small 
carcasses is much less a unit of weight than under the old 
system, when the feeding was continued during a longer 
period. Pigs properly fed are now wisely turned off at 
the age of a few months, excepting, perhaps, in those 
localities where a slow early growth is cheaply secured on 
pasturage. 

473. Character of the growth in pork production. — ^The 
modern hog is emphatically a fat-producing organism, 
having a capacity in this particular greatly surpassing 
any other species of domestic animal. The dry matter 
of the carcasses of individual animals has been found to 
consist of over 80 per cent of fat, even after the leaf lard 
was removed, and the average proportion in the dry sub- 
stance of eight dressed pigs, representing six breeds, was 
found by Wiley to be 78 per cent. 



380 



THE FEEDING OF ANIMALS 



The statement of the composition of a Berkshire pig 
and of a Duroc-Jersey will be found interesting in this 
connection: 

Table LXXXIV. Composition of the Entire Dressed Animal, 
Head, Leaf-lard, and Kidneys Removed. (Wiley.) 





Weight 
carcass 


Water 


Dry 
sub- 
stance 


Ash 


Protein 


Fat 




Po\inds 


Percent 


Percent 


Percent 


Percent 


Percent 


Berkshire 


129 


43.1 


56.9 


2.6 


13. 


40.5 


Duroc-Jersey 


149 


30.6 


69.4 


1.8 


9. 


57.7 


Fat pig, entire animal 














(Lawes & Gilbert) . . 


200 


43.9 


56.1 


1.9 


11.9 


42.3 



It appears that there were stored in the part of the 
animal analyzed by Wiley only 13 pounds of protein 
with the Duroc-Jersey and about 17 pounds with the 
Berkshire, the quantities of fat being 52 pounds and 86 
pounds, respectively. The figures for the entire animal, 
as analyzed by Lawes and Gilbert, are at the rate of 
23.8 pounds protein and 84.6 pounds fat, in a pig weigh- 
ing 200 pounds. 

These proportions bring out sharply the character of 
the growth with swine. It is to be noted that in no other 
species, very fat sheep possibly excepted, does the body 
consist so largely of dry matter, which means that the 
increase of a unit of live weight involves the storage of 
more food substance than with other domestic animals. 
The data at our command warrant the statement, in a 
general way, that when a pig gains 1.5 pounds daily in 
live weight he stores not less than .84 pound of dry sub- 
stance, of which .18 pound is protein and .63 pound is 
fat, these figures representing the average growth during 
the life of the animal. Lawes and Gilbert estimate that 



FEEDING FOR MEAT 381 

the increase of pigs while fattening has the following com- 
position : 

Water Dry substance Ash Protein Fat 

Per cent Per cent Per cent Per cent Per cent 

22 78 .10 6.4 71.5 

According to these figures the protein storage, with 
1.5 pounds daily gain, would be only .10 pound and the 
fat 1.07 pounds. 

474. Food requirements for pork production. — Under 
a system of intensive production pigs go to market so 
young that we may properly discuss their feeding from 
birth. We deal first with the mother as a milch animal. 
According to observations by Henry, in an inquiry as to 
the yield and composition of sow's milk, it seems probable 
that in proportion to their weight small sows yield as 
large a quantity of milk solids daily as a good cow. The 
average daily production of milk solids of one animal 
appeared to be about one pound. This w^ould be four 
pounds for four sow^s, which is the equivalent of the solids 
in over thirty pounds of cow's milk of average quality. 
It follows, therefore, that the demands upon the food for 
milk formation are proportionally as heavy with swine 
as w^ith cows, and consequently the ration should be one 
that will stimulate and sustain abundant milk secretion. 
Such feeding is not only necessary, but economical, for 
independent experiments indicate that the food cost of 
the growi:h of pigs before weaning is no greater than it is 
after weaning. 

Skimmed milk or buttermilk combined with a mixture 
of wheat middlings and any of the ground cereal grains, 
barley, oats, or corn, cannot be improved upon as food 
for milch sows. The supply of protein should be liberal. 
The feeding should be quite up to the limits of capacity. 



382 THE FEEDING OF ANIMALS 

and even then the dam suckUng a large Htter of young 
will grow thin. 

475. Pigs unwisely fed. — If we merely consider the 
nature of the body substance of swine in its relation to 
the constructive functions of the nutrients, it would not 
be unreasonable to believe that rations with a wide 
nutritive ratio are adapted to the needs of this class of 
animals for growth. In a certain sense, practice ratifies 
this view. Thousands of fat hogs have been the product 
of almost exclusive corn-feeding, especially during the 
later stages of growth. There is no doubt but that large 
size and an excessively fat condition may be secured 
through a liberal supply of carbohydrate material, but 
such one-sided nutrition is not now regarded as being 
adapted to the physiological requirements of the pig or 
as producing pork which meets the existing demands 
of the market. 

It is doubtful whether any other species of domestic 
animal has been the subject of so much abuse through 
improper feeding, combined with an unhealthful environ- 
ment, as has the pig. We now regard the abnormal 
masses of porcine fat which have heretofore appeared in 
our markets as not only an exhibition of physical mon- 
strosities, but as not serving the health interests of the 
human family. 

476. Point of view in feeding pigs. — ^The primary 
object in feeding pigs should be, as with all domestic 
animals, the securing of a normal and vigorous physio- 
logical development, i. e., an organism with a strong 
bony structure and with such a growth of muscular tissue 
as shall insure full exercise of all the vital functions. The 
view seems to have prevailed, in a practical way at least, 
that pigs can be fed on anything, live and sleep anywhere, 



FEEDING FOR MEAT 383 

and still not suffer ill effects, as would be the case with the 
other farm animals. This has been unfortunate, because 
probably no domestic species is more susceptible to 
abnormal development through improper feeding than 
are swine. It is true, at least, that no other species has 
shown so marked a response to changes in the character 
of the rations, through modifications of the bony struc- 
ture and through variations in the proportions of muscle 
and fat tissue. 

477. Influence of ration on the development of swine. 
— Notable proof of the plasticity of the pig's organism 
was supplied by the experiments of Sanborn and Henry 
in comparing rations extremely nitrogenous with those 
extremely carbohydrate in character. Pigs fed liberally 
on blood, milk, and shorts combined with more or less 
corn meal, made growth more rapidly, had stronger bones, 
larger organs, and more muscular tissue than those fed 
on corn meal or a mixture of corn meal mth other highly 
non-nitrogenous materials, such as potatoes and tallow. 
The latter combination was deficient both in protein and 
in bone-forming compounds. Such marked differences 
are not usually seen, because rations are not generally so 
extremely one-sided. These experiments teach the 
lesson, though, that as much care should be exercised in 
choosing the pig's ration as the cow's. 

Experimental observations demonstrate that the pig's 
ration should be selected with reference to supplying an 
abundance of bone-making material and a reasonably 
large proportion of protein. Evidence is not wanting 
that the feeding of wood-ashes and ground bone to grow- 
ing pigs promotes both a normal development of the 
bony framework and a more liberal consumption of food. 
Animals that are grazing may not need to have the ration 



384 THE FEEDING OF ANIMALS 

SO supplemented but it is wise and even necessary with 
those confined in pens. 

478. Dairy wastes as food for pigs. — In selecting 
foods for the production of small pork where the develop- 
ment of all forms of tissue is taking place, first rank must 
be given to the dairy wastes. As a means of promoting 
rapid growth and a condition of health and vigor, and also 
as a supplement to cereal-grain products, skim-milk and 
buttermilk are not excelled, and perhaps not equaled, by 
any other feeding-stuffs. Dairy wastes are more profit- 
ably used in pork production than perhaps in any other 
way. (See Pars. 360-363.) In order to secure the maxi- 
mum result from a given quantity of dairy wastes, they 
should be fed in combination with grain products. When 
this is done, and the proportions of skim-milk or butter- 
milk and grain are what they should be, it appears to 
require less digestible food substance for a pound of 
growth than when grain is fed alone or when the liquid 
food is largely eaten. In other words, dairy wastes are 
not only efficient in themselves in producing growth, 
but in proper combination they cause a. saving of the 
grain products necessary to secure a given ratio of gain. 
Henry states, on the basis of eight feeding trials involv- 
ing the use of ninety pigs, that 462 pounds of skimmed 
milk effected a saving of 100 pounds of corn meal. This 
means that 46.2 pounds of digestible milk solids, when 
combined with corn meal, saved, approximately, 76 pounds 
of digestible corn meal substance. 

Henry's experiments were arranged so as to gain 
information as to the most desirable proportion of milk 
and meal, and from his data the writer has calculated the 
quantity of digestible nutrients required in each com- 
bination for one pound of growth: 



FEEDING FOR MEAT 385 



Digestible matter required 



for 1 pound of gain 
Pc " 



Combination rounds 

Mixed grains alone 3.9 

1 lb. com meal to 1-3 lbs. skim-milk .... 3. 

1 lb. com meal to 3-5 lbs. skim-milk .... 3.1 

1 lb. com meal to 5-7 lbs. skim-milk .... 3.3 

1 lb. com meal to 7-9 lbs. skim-milk .... 3.2 

These results show the greatest food eflSciency with 
the mmimum proportion of skim-milk. Other experi- 
ments, notably those by Linfield and Robertson, give 
similar testimony. With the former, in seven experi- 
ments, a milk and grain ration produced 1 pound of 
gain for each 2.58 pounds of digestible matter, the re- 
quirement with milk alone being 2.85 pounds and with 
grain alone 3.19 pounds. When 2 pounds of skim-milk 
was fed with 1 pound of grain, 100 pounds of the milk 
replaced 31 pounds of grain, but when the milk and grain 
were as 4 to 1, 100 pounds of milk replaced only 24 
pounds of grain. 

Doubtless with pigs in the earliest stages of growth 
after weaning, the proportion of milk to grain may well be 
larger than in the more mature periods, and in any case 
the ratio will naturally depend somewhat on the relative 
supply of the milk and grains. 

479. Protein foods other than milk products for 
swine. — In the absence of dairy wastes, meat meal, dried 
blood, and fish scraps may be used to supplement the 
grain products or a mixture of the more nitrogenous 
feeding-stuffs with corn and barley will be found greatly 
superior to the corn or barley alone. Milk is more efficient 
with young pigs than the graiu feeds rich in protein, but 
in the maturer periods the digestible matter of certain 
of the latter seems to have a value not greatly, if any, 
below that of skim-milk solids. 



386 THE FEEDING OF ANIMALS 

The protein feeds adapted to pigs are gluten meal, 
gluten feed, buckwheat middlings, brewers' wastes, peas, 
and middlings. The oil meals, except in small quantities, 
affect the health of swine unfavorably and wheat bran 
is inferior to middlings. 

Of the carbohydrate foods, oats, barley, wheat, rice 
products, and especially corn, are all useful. Although 
the excessive corn-feeding of swine is to be deplored, this 
grain is second in value to no other in the pig's ration, 
and only needs to be reinforced with more nitrogenous 
feeds in order to find a safe and profitable use. In the 
later stages of growth or fattening it may well form the 
major part of the ration. Probably no combination has 
been found more satisfactory for all around use than 
skim-milk, wheat middlings, and corn meal, the latter 
constituting the larger proportion of the grain food. 

480. Forage crops for swine. — At the present time 
much attention is given to forage crops for swine. Clover, 
alfalfa, rape, sorghum, rye, and ordinary pasturage have 
all been found to be adapted to hogs. When fed with 
grain, economical and satisfactory production is secured. 
When fed alone, the growth is so slow as to be unsatis- 
factory. In two experiments at the Wisconsin Experi- 
ment Station, one acre of rape when combined with grain 
proved to be equal to 2,767 pounds of corn and shorts. 
Other observations show beyond question that such 
feeding is practicable and under some conditions profita- 
ble. Better results seem to follow when the pigs are 
allowed to graze than when the fodder crop is cut and 
fed to animals confined in pens. 



CHAPTER XXII 
FEEDING WORKING ANIMALS 

Working animals are rapidly being displaced by power 
vehicles. Those now in use in the United States are chiefly 
horses and mules. Oxen were once employed extensively 
for farm labor and in limabering, but these are rarely seen 
under the yoke at the present time except in remote rural 
districts. It will be proper, therefore, to treat in this con- 
nection chiefly of horses that are used for draft and road 
piuposes. 

481. The horse a machine. — In feedmg a working 
animal, the essential product of the food is energy to be 
used in drawing, walking, or trotting. The latent food 
energy is made available, as heretofore stated, by the 
oxidation of the several nutrients into the ordinary 
products of combustion, and the units of heat or work 
or other forms of kinetic energy evolved are directly 
proportional to the quantity of digested food which suffers 
combustion, just as the possible work of a steam engine 
under given conditions is proportional to the fuel con- 
sumption in the boiler. The establishment of fundamen- 
tal relations between food and work requires on the one 
hand an understanding of the energy values of food, and 
on the other hand at least a general conception of the 
amoimt of work performed. The energy values of food 
have been considered and it now remains for us to ascer- 
tain what is known concerning energy consumption by a 
laboring animal. 

(387) 



388 THE FEEDING OF ANIMALS 

482. The work performed by a horse. — The labor per- 
formed by a draft or road animal, exclusive of the energy 
required for maintenance, may be regarded as consist- 
ing of two components, viz., the effort of moving the 
load and that of moving the animal's body. If a horse 
weighing 1,000 pounds draws 1 mile a wagon which, with 
its load, weighs 1,500 pounds, 2,500 pounds of matter 
have been moved through the distance traveled. In 
other words, a horse moves himself and his load whether 
the load is drawn on a wagon or is loaded on his back. 

The exact expenditure of energy involved in both of 
these components cannot be measured directly. The work 
of drawing a load may be determined by the use of a 
dynamometer, but it can only be estimated so far as the 
body of the horse is concerned. If the latter factor could 
be calculated on the basis of simply projecting a mass 
of matter through the space traveled, it w^ould be a com- 
paratively simple problem. There is a vertical motion 
of the horse's body to be accounted for, as well as a 
horizontal, and the reduction of both to units of work is 
a difficult matter. If this could be done, our present 
knowledge of the food energy necessary for the per- 
formance of a unit of mechanical labor would allow 
quite definite calculations of the daily food needs of horses 
of different classes. As a matter of fact, the actual work 
accomplished by laboring animals has been and still is 
to quite an extent, a matter of estimation. 

Chardin, a French army veterinarian, estimates that 
the average daily work performed is about 2,580 foot- 
tons. Lavalard calculates that the total ordinary work 
of any army horse equals 8,500 foot-tons. As stated by 
Armsby, the ordinary day's work of a horse is estimated 
at 1,500,000 kilogram meters, or 5,425 foot-tons, this 



FEEDING WORKING ANIMALS 389 

evidently meaning the mechanical labor outside the 
motion of the body. With the knowledge we now possess 
it is possible to estimate approximately the actual work 
performed in a given case. 

It would be a good day's labor if a 1,000-pound horse 
travels 20 miles over a smooth, level, dirt road hauling 
a wagon with a load of 2,000 pounds. The draft of the 
loaded wagon would be not far from 100 pounds. A sim- 
ple calculation shows that the mere moving of such a load 
the distance of 1 mile would be equivalent to 264 foot- 
tons. The energy expenditure in walking a given distance 
has been measured by Zuntz, who ascertained the differ- 
ence in oxygen consumption of a horse when at rest and 
when traveling at a walk over a level road. According 
to these measurements, it appears that a 1,000-pound 
horse in walking 1 mile at the rate of 2 to 3 miles an 
hour would expend a total energy of 473 foot-tons, 44.4 
per cent or 201 foot-tons of which belong to the effort of 
walking, over and above the energy needed for mere 
maintenance. In the case assumed, a horse would per- 
form a total labor, in walking and drawing 20 miles, 
equivalent to lifting 9,300 tons through a space of 1 foot. 
This estimate is presented merely as an approximation 
of the work done under given conditions. 

483. Influence of conditions on the food expenditure 
for a unit of work. — ^These figures are, perhaps, less im- 
portant to the OTVTier of work or driving horses than is 
a knowledge of the influence of speed upon the labor 
expended in a unit of time. "According to Marcey, the 
w^ork accomplished in a given time is proportionate to the 
square of the velocity. His coefficients were 3.42 for 
walking or pacing, 16 for trotting, 28.62 for cantering, 
and 68.39 for a full gallop." This general fact would be 



390 THE FEEDING OF ANIMALS 

applicable to horses under all conditions of labor. More- 
over, it is clearly demonstrated by two investigators 
that the food energy required for a unit of work increases 
with the speed. In other words, a horse that trots 20 
miles a day must have more food than when he walks the 
20 miles. In the same way draft animals require food 
somewhat in proportion to the pace with which they 
travel over a given distance. Grandeau has shown that a 
horse was kept in condition with 19.4 pounds of hay when 
he walked 12J^ miles, but 24 pounds was insufficient 
when he trotted the same distance. Zuntz measured the 
oxygen used for each kilogram meter when a loaded horse 
traveled at different velocities. When the pace was 3 
miles an hour, with a load of 275 pounds, the energy 
required was equal to 4,600 calories for each kilogram 
meter of horse, which increased to 7,753 calories when the 
speed reached 6}^ to 73^ miles an hour. The food needed 
for a unit of work increased nearly 70 per cent in increas- 
ing the speed from 3 to 7 miles. Zuntz shows that if 
a horse exerts himself to the utmost the use of oxygen 
rises at a rapid rate, and that the food consumed for a unit 
of work is nearly one-half more than with ordinary draft. 
It appears to be a rule that as the intensity of exertion 
of the horse increases the food cost of a given amount 
of labor performed increases. Men of experience recog- 
nize this fact in a general way when they insist on favor- 
ing their animals to the slowest pace that is consistent 
with the conditions involved. 

484. The food requirements of a working horse. — 
There are two general ways of ascertaining the food needs 
of a working horse: by practical experiments in which the 
rations are varied until a conclusion is reached as to what 
will support an animal under given conditions, and by 



FEEDING WORKING ANIMALS 391 

determining through scientific investigations the amount 
of work performed in various ways and the relation of a 
unit of food to a unit of work. It would not be far from 
the truth to state, however, that the feeding standards 
which are offered to us through investigations made by 
Boussingault, Wolff, LeClerc, Grandeau, Hoffmeister, 
Lavalard, Zuntz, Kellner, and others, are the outgrowth 
of both practical observations and scientific research, a 
most desirable combination. In a large number of 
instances the kind and quantities of digestible food con- 
sumed daily by working horses have been determined, 
and in many cases the accompanying wastes and gain 
and loss of the animal body have been measured. 

The standard rations now found in German tables 
are the result of such observations. According to these 
standards a 1,000-pound horse requires 11.4 pounds of 
digestible food daily when doing moderate work, 13.6 
pounds for average work, and 16.6 pounds for heavy 
work. With a basal ration of 10 pounds of hay, the grain 
needed to furnish these quantities of digestible nutrients, 
when consisting of a mixture in equal parts of corn and 
oats, would be approximately 11.5 pounds, 15 pounds, and 
20 pounds for the three conditions of labor. Lavalard, 
who made observations covering a period of a number of 
years for 32,000 omnibus, army, and draft horses, has 
reached the conclusion that "a horse performing ordinary 
work requires 115 grams of digestible protein and 1,100 
grams of digestible carbohydrates per 100 kilograms 
live weight." This is at the rate of 1.215 pounds of 
digestible nutrients for 100 pounds of live weight. This 
observer bases the ration upon the weight of the animal, 
but practically concedes that "somewhat larger amounts 
of protein and carbohydrates are considered necessary 



392 THE FEEDING OF ANIMALS 

with small horses," a conclusion which is entirely con- 
sistent with observation and related facts. Lavalard's 
formula would furnish a 1,000-pound horse, doing ordi- 
nary work, with 12.1 pounds of digestible nutrients daily, 
a quantity not inconsistent with the German standard. 
Kellner has recommended the following average stan- 
dards for working horses to include maintenance : 



Requirements of the Working Horse* 

Digestible Energy 

protein value 

Pounds Therms 

For light work 1. 9.8 

For medium work 1.4 12.4 

For heavy work 2. 16. 

Rations corresponding to these standards would be 
as follows: 

For light work For medium work 

10 lbs. mixed hay. 10 lbs. mixed hay. 

5 lbs. cracked corn. 7 lbs. cracked corn, 

2 lbs. wheat middlings. 3 lbs. wheat middlings. 

1 lb. wheat bran. 1 lb. brewers' grains, dried. 

For heavy work 
10 lbs. mixed hay. 
10 lbs. cracked corn. 

4 lbs. wheat middlings. 

1 lb. brewers' grains. 

485. Estimate of work ration for the horse based 
on energy relations. — ^The results of the masterly and 
extensive metabolism investigations which Zuntz had 
carried on with a horse under various conditions may 
properly be used for computing a ration. This investiga- 
tor determined the oxygen consumption, which is equiva- 
lent to ascertaining the ,f ood use, by a horse at rest, when 

♦Based on true protein and productive values. 



FEEDING WORKING ANIMALS 393 

walking on a smooth level without load, and when per- 
forming both light and heavy work. First of all, it appears 
from his observations that 31.6 per cent, or about one- 
third, of the total food energy can be converted into useful 
work. This is much less than the coefficient of useful 
work found by Wolff, whose conclusions Zuntz regards as 
erroneous. But even if Zuntz's figures are none too low, 
it is evident that the animal machine uses fuel with much 
greater economy than a steam engine where the coefficient 
of usefulness might not be over 10 per cent. The figures 
he reached show further that the total expenditure of 
energy by a horse weighing 1,000 pounds in walking 1 
mile equaled 453 foot-tons, which would be furnished by 
.164 pound of digestible food. As 44.4 per cent of this, 
or 201 foot-tons, was due to the effort of walking over and 
above the needs for maintenance, the extra digestible 
food needed per mile of walking was .07216 pound. 

Zuntz also found that when a horse increases the 
external mechanical labor performed, such increase costs 
.001155 pound digestible dry matter for each foot-ton of 
work. On this basis the 264 foot-tons of energy which is 
needed for pulling 1 mile a load with a draft of 100 pounds 
would be furnished by .3049 pound of food matter. The 
total food expenditure, therefore, for walking and a 
draft of 100 pounds over a smooth, level road for 1 mile, 
would be .377 pound digestible nutrients, and for 20 
miles 7.54 pounds. If we add to this the 6.4 pounds needed 
for mere maintenance, we have 13.94 pounds digestible 
matter as the proper ration for a horse doing the work 
stated for a distance of 20 miles. These figures are cer- 
tainly not inconsistent with the standard reached by 
other methods for a horse doing average work. Such a 
calculation is at least useful in showing the direct rela- 



394 THE FEEDING OF ANIMALS 

tion of food expenditure to work performed, and the 
necessity of feeding a laboring animal somewhat pro- 
portionately to what he does. It should be borne in mind 
constantly that when the intensity of effort of the horse 
increases, even if only the same work is performed in a 
shorter time, the food needs for each unit of work are 
greater. If a driver in making the regular number of trips 
to the railroad station needlessly hurries his horse, or if a 
drayman whips his team into a fast walk and then lets it 
stand idle, more food must be consumed than if the slowest 
possible gait was allowed. 

486. Source of the ration for working horses. — In 
treating of this matter we must, in the first place, con- 
sider the digestive apparatus or storage capacity of the 
horse. It is certainly not adapted to the consumption 
of large quantities of coarse food, as is the case with 
ruminants. If a horse at severe labor needs 17.7 pounds 
of digestible dry matter each day, he could get it from hay 
only by eating over 40 pounds — a most absurd require- 
ment. It is especially necessary, therefore, with hard- 
working animals, that the larger part of their nutriment 
comes from the concentrated feeding-stuffs. Ten to 12 
pounds of hay is all a draft horse should consume in one 
day. Working horses on the farm generally eat too 
much coarse fodder. 

The net values of feeding-stuffs are also important 
in this connection. It has been shown that the net energy 
value of a unit of dry matter from hay is less than with 
that from the grains, and consequently when it is neces- 
sary to supply an animal with a large amount of energy 
for external mechanical uses, requiring high feeding, we 
must resort to the grains in order to construct a ration 
of maximum efficiency. 



FEEDING WORKING ANIMALS 395 

487. Nutritive ratio for working horses. — Concern- 
ing the nutritive ratio or proportion of protein in a ration 
designed for working horses, there is a variety of recom- 
mendations. The German standards call for ratios from 
1:7 to 1:6, according to the severity of labor, the daily 
weight of protein for a 1,000-pound horse to be from 1.5 
to 2.5 pounds. This is greatly more protein than is 
recommended by Lavalard, who, on the basis of exten- 
sive experience, declares that 1.15 pounds of protein 
daily is sufficient for ordinary work, this to be increased 
to 1.35 pounds when the labor becomes more severe. 
There is one fundamental fact that is pertinent to a dis- 
cussion of this point, which is that the non-nitrogenous 
constituents of the ration are largely the source of muscu- 
lar energy. As stated before, it was formerly thought 
that muscular effort was sustained at the expense of 
muscular tissue, but when it was found that no more urea 
was excreted by men climbing a mountain than when 
they were much less active, this view was abandoned. 
Later researches have clearly shown that when work 
increases the excretion of carbon dioxid increases in like 
proportion without any important rise in the protein 
exchange. In other words, the carbohydrates and fats 
are largely the fuel that supplies energy for mechanical 
purposes. Common experience ratifies this conclusion 
of science. Many horses and oxen have successfully 
endured severe labor on meadow hay, oats, and corn, 
sometimes the grain being largely the latter. 

A ration properly compounded from ordinary farm 
products, such as silage, roots, meadow hay, legume hays, 
and the cereal grains, will generally contain protein in 
sufficient proportion, and will seldom need reinforcing 
with the nitrogenous feeding-stuffs. It is probably true, 



396 THE FEEDING OF ANIMALS 

however, that when working animals are called upon to 
endure a severe strain material advantage is gained from 
introducing into the ration a small quantity of some 
nitrogenous feeding-stuff, such as beans or oil meal. 

488. Oats for working horses. — One of the opinions 
regarding the feeding of horses, which has w^idely pre- 
vailed and which is still held by many, is that oats in 
liberal proportions are essential to the successful main- 
tenance of road and work horses, especially the former. 
It has been believed, as has been stated, that this grain 
imparts to the horse greater nervous activity or life than 
any other feeding-stuff, and when it was announced that 
"avenine," an alkaloid, had been extracted from oats, 
this was quickly accepted as an explanation of their 
peculiar effect. We have given up the avenine and seem 
likely to modify our views in other ways, for it is becom- 
ing increasingly evident that other grains may be sub- 
stituted for oats with no detriment to the horse and with 
a material saving to his owner. Barley, brew^ers' grains, 
maize, maize cake, wheat, wheat bran, wheat middlings, 
have been extensively and safely fed in the place of 
oats, wholly or in part, by experiment stations and in 
practice by omnibus and horse-car companies. In this 
way the cost of maintaining horse labor is materially 
decreased, for usually oats are comparatively much more 
expensive than other grains and the by-products in pro- 
portion to their feeding value. It is often the case that 
a farmer can afford to sell a part of the oats he raises and 
buy other grains, and he can do this with confidence that 
he will be able to maintain his road and working horses 
in proper flesh, good health, and spirit on the cheaper 
materials. A great variety of grain mixtures may be used 
successfully in feeding horses. 



FEEDING WORKING ANIMALS 397 

489. Suggested rations for working horses. — ^As a 

suggestion to feeders concerning the ways in which 
several feeding-stuffs may be combined so as to furnish 
practically the same quantity of digestible organic mat- 
ter, the following rations are presented as meeting the 
needs of a horse weighing 1,000 pounds and doing mod- 
erate work: 

ilO lbs. timothy or mixed hay. HO lbs. hay. 

11 3^ lbs. oats. \ 5 lbs. com. 

V 43^ lbs. barley. 

no lbs. hay. HO lbs. hay. 

< 103^ lbs. oats and com, equal < 5 lbs. com. 
V parts by weight. v 63^ lbs. wheat bran. 

no lbs. hay. HO lbs. hay. 

s lOy^ lbs. oats and barley, equal \ 5 lbs. com. 
\ parts by weight. V 6 lbs. brewers' grains. 



10 lbs. hay. AO lbs. hay. 

8 lbs. oats. J 43^ lbs. barley. 

4 lbs. brewers' grains. j 4 lbs. wheat bran. 

' 3 lbs. brewers' grains. 

10 lbs. hay. / 10 lbs. hay. 

8 lbs. oats. 13/4 lbs. com. 

4 lbs. wheat bran. \ 4 lbs. wheat bran. 

\ 4 lbs. brewers' grains. 



Silage, roots, and other green materials may often be 
substituted for a minor part of the hay with advantage 
to the animal's appetite and health. 

No definite rations are suggested for more severe 
labor. The amount of food must simply be increased 
with the amount of work performed. Any increase should 
apply to the grain and not to the hay, the proportions 
of the several feeding-stuffs in the grain ration to remain 
the same in the larger quantity. It is well understood, of 
com*se, that a ration should increase proportionately 



398 THE FEEDING OF ANIMALS 

faster than the amount of work done, and that an old 
animal generally demands higher feeding than does a 
young one. The condition of the road, the intensity of 
the effort, and other circumstances also modify the needs 
of the working horse, so that the feeder is always called 
upon to exercise the trained judgment which comes frona 
experience. No working animal can be fed successfully 
by mechanical rules. 



CHAPTER XXIII 
THE FEEDING OF POULTRY 

By William P. Wheeler 

Under moderate climatic conditions some profit is 
possible with poultry, oftener than with large animals 
now, without very critical attention to the food-supply. 
This is because much of the food natural to birds, and often 
some of the best and cheapest, cannot be utilized except 
as selected and found by the fowls themselves. It is 
even necessary for the best results with certain species to 
provide some approximation to the feeding habits of the 
once wild parents. Nevertheless, artificial conditions must 
be met for part of the year, and continued success cannot 
be assured without full consideration of the essential 
food requirements so far as they may be known. 

490. Food needs of birds intensive. — One pronounced 
characteristic of birds is an intense vitality. Their life 
is never sluggish. The growth of the young and the trans- 
formation of food into eggs are exceedingly rapid. The 
temperature is high, running with certain species from a 
little above 100° F. to 112° or more. The energy expended 
in this direction is proportionately great and material 
for its supply is in urgent demand ; for a vigorous animal is 
the seat of rapid metabolic change. The large appetite 
is an indication of the extensive needs. The very active 
digestive apparatus must be in good order and supplied 
with efficient food. 

The domestic fowls may be classed with the large 

(399) 



400 THE FEEDING OF ANIMALS 

number of birds as omnivorous. While seed-eaters like 
the common fowl are able to subsist for long periods on 
grain alone, as can also the goose by grazing, the natural 
food of most young birds is largely animal. Many wild 
birds which feed almost entirely on seeds supply their 
rapidly-growing young with an abundance of animal food. 
491. Kinds of foods for poultry. — It is a common 
experience that better success follows the use of several 
foods combined rather than a few and it seems to be a 
fact that some variety is essential. While in practice a 
combination must be employed for best results which 
are partly due to the usually greater palatability and 
other indirect effects on the general health, it is not 
because of a greater nutritive value of the constituents 
from different sources that the different foods are needed. 
The important consideration seems to be the proportion 
of constituents. In experiments made at the New York 
Agricultural Experiment Station, the better results from 
rations containing animal food were found to be largely 
due to the greater amount of mineral matter, chiefly 
phosphate of lime, in the animal food used. When rations 
of grains naturally lacking in ash-content were supple- 
mented by bone ash, their efficiency was increased with- 
out addition of other food. For chicks, during the periods 
of most rapid growth, the rations of vegetable origin sup- 
plemented by material rich in phosphate of lime were 
equal or even superior to rations supplying large quan- 
tities of animal protein and fat. For laying hens the 
time during which such rations were equally efficient was 
limited to a few months. Rations containing animal food 
were much superior for ducklings, although the addition 
of bone ash to rations of grain and other vegetable food 
notably increased their efficiency. 



FEEDING OF POULTRY 401 

Although it is possible, for some purposes, to com- 
pound effective rations from grain alone when the defi- 
ciency of ash is made good, it is better in practice to use 
some animal food. A variety of grain food supplying 
enough nitrogenous matter is not always to be found, and 
animal foods when rich in protein, as most of them are, 
prove of great service; for with them can be freely fed 
some of the cheaper, starchy foods, typical among which 
is the palatable and remarkably efficient Indian corn. For 
fattening mature fowls, animal food is not so important 
except when its use improves the palatability of the 
ration. This last is a matter always to be considered. 

Succulent vegetable foods are eagerly eaten by do- 
mestic fowls. Aside from the beneficial effect on the 
health of the birds, it is important to use such foods as 
far as possible, for the nutriment they supply is cheaply 
obtained. With most rations the more nitrogenous 
fodders, such as clover, alfalfa, and very immature 
grasses, are best. These foods also contain more of the 
needed lime than do grains. It must be remembered, 
however, that fowls are not fitted to depend largely on 
such bulky materials while production is rapid. The 
goose is better adapted than most birds to live by grazing, 
but the liberal use of the more concentrated grain and 
animal foods has been found necessary except during 
the idle season. 

At the time of greatest egg production the choice of 
bulky foods should preferably be confined to those of the 
most tender and succulent nature. Certain experiments 
also indicate that a ration which contains any considera- 
ble proportion of dry or woody coarse fodder, although 
finely ground, is not suited to young chicks, and that 
only the more succulent kinds of bulky foods, like the 



402 THE FEEDING OF ANIMALS 

first shoots of grasses and clovers, should be fed in the 
fresh condition. After the birds approach maturity and 
growth is slower, so that a much larger proportion of the 
food is used for maintenance, and during colder weather 
when the heat from the extra energy required for diges- 
tion is useful, more of the coarse foods can be fed with- 
out apparent disadvantage. 

492. Incidental effects of the food with lajdng hens. — 
Another reason, sometimes a very important one, for 
using such foods as young clover, fresh or dried, is the 
effect on the color of the egg yolk. Eggs from hens which 
are fed only certain grain and animal substances gener- 
ally have yolks of a pale yellow color. This is often 
objected to by those who have a preference for eggs with 
darker orange-colored yolks. The liberal feeding of fresh 
or dried young clover, alfalfa, or grass will generally 
insure the deeper coloration. The cause for this frequent 
lack of what may be considered the normal yellow color 
of the egg yolk is not well known, but the occurrence of 
the pale color can be generally prevented by attention 
to the food. 

At the New York Experiment Station, pens of hens 
which were fed alike except that no hay or green food 
was given to one, while three others had different amounts 
apportioned by geometrical ratio, of clover hay alter- 
nated with green alfalfa, produced eggs showing marked 
differences in color. The orange-yellow shade of the 
yolk corresponded directly in intensity with the propor- 
tion of hay or green fodder in the ration. The greenish 
color of the white also varied but not so regularly. Eggs 
from each lot were very uniform in appearance. 

The differences in flavor and other qualities which 
are probably caused by the food cannot be satisfactorily 



FEEDING OF POULTRY 403 

explained at present. They are, however, sHght with 
normal rations. In general the color of the shell is deter- 
mined by the breeding or by the individual characteristics 
of the fowl. 

493. Digestive apparatus of birds (Fig. 17). — ^The pro- 
cess of digestion with birds is essentially similar to that with 
mammals although there are important differences in the 
apparatus by which it is accomplished. It is necessary 
to know something of the general arrangement and 
working of the digestive canal when attempting to estab- 
lish proper methods of feeding, and for a better selec- 
tion and combination of suitable foods. 

Although some extinct species of birds were well 
supplied with teeth, existing forms have the mouth 
armed only with a horny beak. The common fowls 
must swallow grains whole but are able to tear some 
food into small fragments, which they particularly do 
when feeding the young. Ducks, and geese more especi- 
ally, have the mouth supplied with laminse which serve 
to cut soft herbage. 

In birds the salivary glands are small and the lim- 
ited amount of saliva probably has little effect on the 
food. 

The esophagus is of great caliber and very expan- 
sible. It is dilated in the cervical portion in ducks and 
geese. In gallinaceous birds, instead of this dilatation 
there is attached to, and forming practically a part of, 
the esophagus, the reservoir called the crop. The food 
is temporarily retained in the crop, but is changed very 
little other than being softened by the water swallowed 
with it, the small amount of mucus, and the inconse- 
quential amount of saliva. The high temperature doubt- 
less assists this softening effect, and fermentation also 



404 THE FEEDING OF ANIMALS 

progresses rapidly when food is retained long in the crop 
from injury or by overloading with coarse material. 

The divided crop of pigeons secretes, with both sexes 
for several days after the young are hatched, a thick 
milky fluid which serves to feed the young birds. With 
other domestic birds the crop serves for httle more than 
a temporary retaining reservoir. 

The stomach, which is a single organ in some birds, 
is represented by two reservoirs in domestic fowls. The 
first, through which the food passes after leaving the 
crop, is the glandular stomach, the succentric ventricle 
or proventriculus, and the second, closely connected, is 
the gizzard or muscular stomach. The first, from its 
structure, has been considered the true stomach, but it is 
now believed that gastric juice is secreted in the gizzard. 
The food does not accumulate in the first stomach but 
in passing through carries along such juices as are 
there secreted. 

The gizzard is a powerful grinding apparatus. There 
is a strong lining which is capable of resisting great 
pressure and the action of the sharp sand and pebbles. 
In this organ the grains and seeds, with other materials, 
are more finely ground than by the mastication of many 
other animals. 

The intestines are long in domestic fowls. While 
serving the same purpose as in mammals and having 
a general resemblance to the mammalian form, they do 
not clearly show the same divisions. The diameter is 
about the same throughout. The caeca, each of which is 
closed at one end and opens into the intestines at the 
other, seem to be important and essential modifications 
of that canal. Each caecum is from 6 to 7 inches long 
in mature fowls. Not far from the openings of the caeca 



FEEDING OF POULTRY 



405 



the intestine ends in a dilatation, the cloaca, into which 
the genito-urinary passages also open. It is because of 
the mixing here of the undigested residues of the food 
with the secretions from the kidneys and with some other 




% ToRcue 

* esophacus , first postioh 

3 Crop 

4 EsOPMftUS , SrcOND roRTlON 

5 SueCfNTdie VfNTRICLE 

6 OlZZARD 

7 Origin of duodenum 
ft Second bmmcm of duodenal FiExTu/te 
9 Oriqin or tlo/tinq ronTioN of sm^ll iNTtsriNe 

10. :0 SmHL miESTlNE 
11.11 C/ECA 

12 Insertion of C/Ec* 

1 3 7?ECTUM 

\^ Cloaca 
15-15 Pancreas 

i7 Qail-bladdeh 
18 SnrfN 



Fig. 17. Digestive apparatus of the common fowl. 



406 THE FEEDING OF ANIMALS 

products of metabolism, that an accurate estimation of 
the digestibiUty of food by birds is so difficult. No satis- 
factorily accurate methods for separating some of the 
nitrogenous residues from different organs seem yet to 
be perfected. 

Into the intestine shortly after it leaves the gizzard 
two ducts from the liver and two from the pancreas enter, 
discharging the bile and pancreatic j-uices. The liver, as 
usual, is a large organ. The pancreas also is very largely 
developed, and extends for several inches along the duo- 
denal loop of the intestines, reaching in the common 
fowl a length of over 5 inches. 

Altogether the structure of the digestive apparatus of 
birds indicates extreme efficiency and the capacity for 
rapid work. A study of it suggests, also, as does that of 
any complicated and delicately adjusted apparatus, that 
it should not be overloaded nor violently disturbed when 
running at high pressure. It may be said to run at high 
pressure while the extremely rapid growth of young 
birds occurs and during the extended laying season, for 
the resulting products call for an uninterrupted supply 
of food and the transformation of all material that is 
available. Chickens of two pounds weight at ten weeks 
of age show a gain over the weight of the first week of 
nearly 1,700 per cent. Ducklings five pounds in weight 
at nine weeks show a gain during about eight weeks of 
3,900 per cent. Such rates of growth are not very unusual 
for young fowls under favorable conditions. 

494. Constituents of the body of the hen. — ^Whether 
the production of meat or of eggs is the prime object, 
the young fowl must first be grown. It is desirable, then, 
to consider what constituents make up the body of the 
animal, for all must be derived from the food. Many 



FEEDING OF POULTRY 407 

slight variations in composition exist, of course, but there 
is always a certain approximation to the normal full- 
grown animal. 

In the whole body of the common fowl, unless especi- 
ally fattened, not far from one-half of the dry matter is 
protein and about 8 per cent ash. This of itseK would 
suggest that a slow growth must follow the use of foods 
containing small amounts of nitrogenous and mineral 
matter. 

Analyses made, mostly by Jenter at the New York 
Experiment Station, give as the average composition 
of the body of a Leghorn hen, typical of the laying breeds, 
55.8 per cent of water, 21.6 per cent of protein, 3.8 per 
cent of ash, and 17 per cent of fat. This is not the com- 
position of the edible portion alone nor of the carcass as 
found in the market, but that of the whole body, bones, 
blood, feathers, and all the viscera. The different parts 
of the body were all separately analyzed. Separate analy- 
ses of four individual hens each gave a close approxima- 
tion to the average. The composition of the body of a 
Leghorn pullet in full laying was little different from the 
average for the hens, being 55.4 per cent of water, 21.2 
per cent of protein, 3.4 per cent of ash, and 18 per cent 
of fat. 

The body of a mature capon (Plymouth Rock) con- 
tained 41.6 per cent of water, 19.4 per cent of protein, 
3.7 per cent of ash, and 33.9 per cent of fat. If the extra 
amount of fat were removed, the composition would be 
very similar to that of the other fowls. In younger and 
immature birds the percentage of fat is very much less 
than in older birds. 

495. Composition of eggs. — ^The egg, which aside 
from the shell is potentially a chick, shows in the general 



408 THE FEEDING OF ANIMALS 

proportions of the constituents a striking resemblance to 
the body of the grown bird. Of the dry matter of eggs 
analyzed, aside from the shell, 49.8 per cent on the aver- 
age was protein, 3.5 per cent ash, and 38.6 per cent 
fat. Of the dry matter of the bodies of hens 48.9 per 
cent was protein, 8.6 per cent ash, and 38.5 per cent fat. 
Of the total dry matter in the entire egg, 35.6 per 
cent is ash, 25.9 per cent fat, and about 33.3 per cent pro- 
tein, or 38.5 per cent if estimated by difference. The 
fresh egg with a good firm shell consists of about 11.4 per 
cent shell, 65.7 per cent of water, 8.9 per cent of fat, 11.4 
per cent of protein by factor, or 13.2 per cent by differ- 
ence, and .8 per cent of ash constituents aside from the 
shell. Of this ash 53.7 per cent is phosphoric acid. Over 
.2 per cent of the edible portion of the egg is phosphorus. 
This composition is the average from twenty-four analy- 
ses by Thompson, and eighteen by Wheeler, represent- 
ing over 400 eggs from hens of several breeds under dif- 
ferent rations. None of the analyses differed much from 
the average. 

496. Necessity for considering the water-supply. — 
In the products, which have been mentioned, as in most 
animal products sought by feeding, there is always a 
large amount of water. In every dozen eggs there is a 
pint of water. Aside from that necessary for construc- 
tive use there is required for the activities of the living 
animal a free supply. Particular mention is made of the 
necessity for water, because its great importance is some- 
times overlooked, for an especially provided supply is 
not necessary under some circumstances. Instances occur 
when the lack of water is the cause of ill success. 

497. Efficiency of protein from animal sources for 
fowl. — ^Mention of the characteristics and composition 



FEEDING OF POULTRY 409 

of the different nutrients of the food and a discussion of 
their functions will be found elsewhere in this volume. 
The facts apply to the feeding of poultry as well as to 
that of other animals. 

It appears from present knowledge that protein 
derived from animal sources is more efficient for certain 
uses, particularly the feeding of ducklings, than that 
derived from vegetable foods. Previous mention has been 
made of experiments at the New York Experiment Sta- 
tion, the results of which accord with this assumption. 
The rations which contained animal food proved much 
more efficient than those of vegetable origin, the latter 
having, according to the ordinary methods of estimation, 
the same nutritive value as the former. 

498. Ash constituents important for egg production. — 
It seems probable that the ash constituents have some- 
times not been sufficiently considered in feeding. While 
the importance of the mineral nutrients can be largely 
overlooked without serious practical disadvantage when 
feeding some animals for certain purposes, it must be 
given consideration when feeding domestic fowls. WTiile 
in milk, for instance, about 5 per cent of the dry matter 
is ash, in eggs over 35 per cent of the dry matter is repre- 
sented by the mineral constituents. 

The shell of the ^gg, which represents about 11 per 
cent of the fresh ^gg, consists almost entirely of carbonate 
of lime. Most grain foods, w^hich naturally constitute the 
bulk of ordinary rations, contain little mineral matter 
and the amount of lime is notably low. For simply sup- 
plying the deficiency of material for the egg shell, car- 
bonate of lime in the form of oyster shell can be used. 
This w^as showTi in experiments at the New York Experi- 
ment Station made with laying hens after they were 



410 THE FEEDING OF ANIMALS 

closely confined on a clean floor for over three weeks. It 
was then found that about nine-tenths of the lime in the 
egg shell was unaccounted for in the food aside from the 
oyster shells which were fed. 

WhUe less than 10 per cent of the body of a fowl is 
mineral matter, it consists largely of phosphate of lime 
and exceeds in proportion that of many foods. The bony 
framework is also rapidly formed in the growing bird so 
that mineral matter is in imperative demand. The 
results of many trials made at the New York Experi- 
ment Station are clearly in accord with this assumed 
need. As has been previously mentioned, the addition 
of phosphate of lime from several sources to rations for 
young fowls has noticeably increased their efficiency. 

499. Common salt a necessity for fowls. — Common 
salt in considerable quantity is a necessity to the living 
animal. Some foods contain a probably sufficient amount 
but in others the proportion is very small. In order to 
make sure of an excess, and to avoid any possible defi- 
ciency, it is well to add salt regularly to the food, espec- 
ially when it also increases the palatability of the ration. 
About five ounces in every 100 pounds of food has been 
found a safe proportion. Fowls regularly accustomed to 
salt are not likely to eat an injurious quantity of very 
salty material when it is accidentally within their reach. 
Pigeons are very fond of salt and a liberal allowance is 
generally considered necessary to insure health in the 
loft. 

500. Supply of grit for fowls. — Fowls at liberty are 
generally able to find grit enough in the form of sharp 
pebbles and sand to facilitate the grinding which occurs 
in the gizzard. When they are confined or do not have 
extended range, sharp and hard grit of some kind should 



FEEDING OF POULTRY 411 

always be freely supplied. Clean, sharp sand is useful 
for the very young birds and is quite generally considered 
an essential part of all mixtures fed to ducklings. Good 
results accompany its free use. 

601. Feeding standards for fowls. — In studying and 
comparing different rations, it is not possible to consider 
all the combinations that can be made of the many foods. 
It is only practicable to consider foods with reference to 
their varying proportions of constituents. The only 
portion of these constituents of nutritive value is that 
which can be digested. Therefore, in compounding 
rations, we are guided primarily by the amount of the 
digestible nutrients supplied by the food; and feeding 
standards are for convenience limited to a statement of 
the assumed requirements in terms of digestible pro- 
tein, ash, carbohydrates, and fat. The bulk of the ration 
supplying these nutrients must also, of course, fall within 
certain limits. In the absence of enough specific data, 
calculations must be based on the coefficients of digesti- 
bility observed for other animals. These afford safe 
enough approximations for present use, for the feeding 
standards must be largely provisional. 

Growth and egg production can only be sustained by 
the food in excess of that required to support life, although 
egg production can temporarily occur at the partial 
expense of the body. The amount of food, then, required 
for simple maintenance puts a limit on one side to an 
eflScient and profitable ration. In the other direction, it 
is only limited by the capabilities of the individual ani- 
mal. So the highest possibilities depend altogether on 
the intelligent judgment, and careful, daily attention of 
the experienced feeder. In a general way only averages 
can be considered. 



412 



THE FEEDING OF ANIMALS 



502. Maintenance rations for fowls. — A number of 
feedings trials made at the New York Experiment Sta- 
tion supply information relative to the amount of food 
required for simple maintenance. The amount varies, 
as might be expected, with the size of the animal. The 
larger fowls required more food but much less for each 
pound of live weight. These feeding trials did not cover 
any molting-period and egg production was, for the time, 
suspended. From the data secured maintenance rations 
have been deduced which correspond very closely to 
those actually fed for quite extended periods during 
which practically no change in live weight occurred. The 
data were from an aggregate of 52 capons, averaging by 
different lots from 9 to 12 pounds in weight, for 158 days* 
feeding, and from 60 hens ranging from 3 to 7 pounds in 
weight for 150 days' feeding. 

The rations are stated in the following tabulated form : 



Table LXXXV. Maintenance Rations. Digestible Nutri- 
ents A Day for Each 100 Pounds Live Weight 



Total dry 
matter 



Ash 



Protein 



Carbohy- 
drates 



Fat 



Fuel 
value 



Nutritive 
ratio 



Capons of 9 to \2 lbs. wt 
Hens of 5 to 7 lbs. wt. 
Hens of 3 to 5 lbs. wt. 



Lbs. 
2.3 
2.7 
3.9 



Lbs. 
.06 
.1 
.15 



Lbs. 
.3 
.4 
.5 



Lbs. 
1.74 
2. 
2.95 



Lbs. 
.2 
.2 
.3 



Cal. 

4,600 

5,300 

7,680 



1:7.5 
1:6.2 
1:7.4 



503. Rations for lajdng hens. — Hens in full laying 
seem to require rations which have a larger relative con- 
tent of protein and ash, and which show an increase in 
fuel value of from 15 to 40 per cent, according to size, 
over those required for maintenance. The following 
standards approximate the requirements for two general 
groups not sharply separated. 



FEEDING OF POULTRY 



413 



Table LXXXVI. Rations for Hens in Full Laying. Di- 
gestible Nutrients a Day for Each 100 Pounds Live 
Weight. 



Hens of 5 to 8 lbs. wt. 
Hens of 3 to 5 lbs. wt. 



Total dry 
matter 



Lbs. 
3.3 



Ash 



Lbs. 

.2 

.3 



Protein 



Lbs. 
.65 
1. 



Carbohy- 
drates 



Lbs. 
2.25 
3.75 



Fat 



Lbs. 

.2 

.35 



Fuel 
value 



CaL 

6,240 
10,300 



Nutritive 
ratio 



1:4.2 
1:4.6 



These standards are not absolute and inflexible rules, 
for such would not be justified by a thousand times the 
number of available data. They supply a definite start- 
ing point and are not supposed to obviate the use of judg- 
ment. Because it is found convenient, on account of 
different requirements and capabilities, to divide hens 
into two groups, it should not be presumed that a hen just 
under five pounds in weight must always have one ration or 
a hen just over five pounds must always have the other. 

A ration which corresponds to the standard given for 
maintenance for hens of the larger size could be com- 
posed of one pound of cracked corn, one pound of corn 
meal, one-half pound each of ground oats, wheat mid- 
dlings, and clover hay, one-fourth pound of fresh bone 
and two ounces of meat scraps. 

The following stated ration is given as an illustration 
of one which would supply the nutrients called for in the 
standard for laying hens of the larger size: One pound 
of cracked corn, three-fourths pound of wheat, three- 
fourths pound of corn meal, one-half pound each of wheat 
middlings, buckwheat middlings, and animal meal, two- 
thirds pound of fresh bone, and three-fourths pound of 
young green alfalfa. 

504. Rations for yoimg birds. — ^The requirements of 
the rapidly-growing young fowl are so constantly chang- 



414 



THE FEEDING OF ANIMALS 



ing that a satisfactory average ration for any extended 
period cannot be easily formulated. In the following 
statement of rations for chicks, they are averaged for 
periods of two weeks at different ages dm-ing the time of 
most rapid growth. The ration for the last period will 
suffice for several weeks longer, although the amount 
required to the 100 pounds live weight will gradually 
diminish up to maturity. For fattening nearly mature 
fowls, a ration with a wider nutritive ratio of about 1 : 8 
can be liberally fed for limited periods. 

The duck grows faster than the common fowl and 
more food is required during an equal time. Rations for 
ducklings differing somewhat from those for chicks are 
given separately. 

Table LXXXVII. Rations for Chicks. Digestible Nutrients 
A Day for Each 100 Pounds Live Weight 





Total 

dry 

matter 


Ash 


Protein 


Carbohy- 
drates 


Fat 


Fuel 
value 


Nutri- 
tive 
ratio 




Lbs. 


Lbs. 


Lbs. 


Lbs. 


Lbs. 


Cal. 




For the first 2 weeks . 


10.1 


.5 


2. 


7.2 


.4 


18,800 


1:4.1 


From 2 to 4 weeks of age 


9.6 


.7 


2.2 


6.2 


.5 


17,730 


1:3.4 


From 4 to 6 weeks of age 


8.6 


.6 


2. 


5.6 


.4 


15,640 


1:3.3 


From 6 to 8 weeks of age 


7.4 


.5 


1.6 


4.9 


.4 


13.780 


1:3.7 


From 8 to 10 weeks of age 


6.4 


.5 


1.2 


4.4 


.3 


11,680 


1:4.3 


From 10 to 12 weeks of age 


5.4 


.4 


1. 


3.7 


.3 


10,000 


1:4.4 



Rations for Ducklings. Digestible Nutrients 
Each 100 Pounds Live Weight 


A Day for 




Total 

dry 

matter 


Ash 


Protein 


Carbohy- 
drates 


Fat 


Fuel 
value 


Nutri- 
tive 
ratio 


For the first 2 weeks 
From 2 to 4 weeks of age 
From 4 to 6 weeks of age 
From 6 to 8 weeks of age 
From 8 to 10 weeks of age 
From 10 to 15 weeks of age 


Lbs. 
17.2 
17. 
11.2 

8. 
7. 
4.6 


Lbs. 
1.6 
1.5 
.8 
.6 
.5 
.3 


Lbs. 
4. 
4.1 
2.7 
1.7 
1.4 
.9 


Lbs. 
11.2 
10.1 
7. 
5.2 
4.7 
3.2 


Lbs. 
1.4 
1.3 
.7 
.5 
.4 
.2 


Cal. 
34,180 
31,900 
21,000 
14,940 
13,030 

8,470 


1:3.7 
1:3.2 
1:3.3 
1:3.8 
1:4.1 
1:4.1 



FEEDING OF POULTRY 415 

As an example of a day's ration which would cor- 
respond to the requirements of the standard given for 
young chicks during the second week the following is 
stated: Four pounds of cracked wheat, two pounds of 
granulated oatmeal, three pounds of corn meal, one-half 
pound each of wheat middlings, buckwheat middlings, 
ground oats, and old process linseed meal, two and one- 
fourth pounds of animal meal, and two and three-fourths 
pounds of young green alfalfa. This would feed from 
800 to 1,000 chicks of this age. 

Another ration in accord with the standard given 
for ducklings about three wrecks old might be consti- 
tuted as follows: Eight pounds corn meal, three pounds 
wheat middlings, two pounds ground barley, two pounds 
of old process linseed meal, six pounds of animal meal, 
two pounds of fresh bone, and three pounds of young 
green alfalfa. This and other specimen rations are given 
under the assumption that free supplies of sharp grit, as 
well as water, are also provided. 

505. Adaptability of various foods for fowls. — ^A con- 
sideration of the adaptability of the different foods, 
aside from their composition, and of the apparent require- 
ments of the young at different periods suggests a ration 
somewhat wider in nutritive ratio for the first few days 
than for some weeks afterward. 

In providing a ration, it may be possible to devise 
one in accord wdth the formal standard which will be 
decidedly inefficient at times if the chemical composi- 
tion and coefficients of digestibility are alone considered. 
The adaptability of foods that are palatable must be con- 
sidered. The difference in the energy required to digest 
various foods which can supply equal proportions of 
digestible matter may be important sometimes. 



416 THE FEEDING OF ANIMALS 

A large number of the ordinary grains seem prac- 
tically interchangeable and many grain by-products can 
be freely substituted for different whole grains or for 
each other and all combined as desired. But some foods, 
such as cottonseed meal, do not seem suited to common 
fowls, even in very small quantities. Linseed meal can 
be fed more freely, but the unground flaxseed is less 
satisfactory. It is probable that oats, whole or ground, 
which appear so valuable sometimes, should not be freely 
used at other times. About 30 per cent of the entire 
grain is hull. To obtain the available material from this 
requires an expenditure of energy that can be better 
applied during periods of rapid transformation, espe- 
cially during the first few weeks of the young bird's growth. 
The products of the oat kernel, however, from which 
the hull has been separated are in the unquestioned class 
of foods. The same observation applies to buckwheat, 
some kinds of pea meal, and to certain other foods less 
commonly used, containing a large proportion of crude 
fiber. Reference to this point has been made before under 
the topic of coarse and bulky foods. 

Primary consideration has naturally been given to 
those domestic fowls upon which we depend for the 
great bulk of eggs and meat. Other kinds are of consider- 
able importance in certain localities, or often to the 
fancier, but concerning them not enough is recorded to 
establish separate feeding standards. It is probable that 
their requirements will be found to correspond fairly 
well with those of either the duck or of the common fowl. 
The general food of the turkey is similar to that of the 
common fowl but it should be less artificial, and con- 
ditions of general feeding, more nearly resembling those 
which exist in a wild state, are required. 



FEEDING OF POULTRY 417 

506. Knowledge of the nutrition of fowls limited. — 

Unsatisfactory as is our present knowledge of the funda- 
mental laws which underlie the science of nutrition 
applied to man and other animals, there are nevertheless 
volumes of carefully collected data that make it possible 
to ascribe fairly narrow limits to their operations. Com- 
pared with mammals, however, the class of birds has 
received very little consideration. There have been a 
few careful studies made, but for lack of enough informa- 
tion our feeding must be guided by the rules applying in 
common to all animals. Undoubtedly, the accepted laws 
of nutrition observed for other animals are applicable in a 
general way to domestic fowls, and it is safe to apply in 
the light of the specific data we have any general prin- 
ciples of feeding that have already been established. This 
has been done in formulating the feeding standards which 
are here presented, and all available data of a reliable 
character have been considered. There have not been 
enough, however, to justify narrow limitations, and the 
suggested standards should not be considered final and 
unchangeable. They simply represent the averages of 
rations which, under careful management and like con- 
ditions, have given better results than various other 
rations with which they have been contrasted. Slight 
modifications were made in accord somewhat w^th the 
habits of the different fowls and with a consideration of 
the character of the products desired. It is important 
that the feeder, while following such standards in a gen- 
eral way, should give enough consideration to the sub- 
ject to make modifications suited to the species and breed 
and to his particular conditions of market and farm. 



AA 



CHAPTER XXIV 
THE RELATION OF FOOD TO PRODUCTION 

One of the questions much discussed by farmers, 
and which has an important bearing upon the economics 
of animal husbandry, is the food cost of the various 
animal products. To illustrate, a herd of cows consumes 
a certain quantity of food and produces a certain weight 
of milk, milk solids, cheese, or butter, according to the 
terms in which we state the production. If the same 
food is fed to a lot of steers a certain increase in their 
live weight is secured. There is in each case a relation 
of quantity between the food and the product. The food 
cost, that is, the food consumption, involved in growing 
a pound of beef, is quite unlike the food requirements for 
producing a pound of pork, a pound of veal, or a pound 
of eggs. If we consider merely food expenditure, that 
branch of animal husbandry is most economical of raw 
materials in which the largest proportion of the food dry 
substance is converted into some new, useful product, or, 
differently stated, where the food units bear the lowest 
ratio to a unit of product. 

507. Food xinit defined. — In presenting the matter it is 
necessary to first define our units. Certainly it cannot be a 
pound of food as eaten. One farmer feeds his cows silage or 
roots, and grain, with but little hay, while another fattens 
steers on dry food alone. A comparison of production in 
the two instances on the basis of the gross weight of food 
consumed would be absurd, because with the cows the 

(418) 



RELATION OF FOOD TO PRODUCTION 419 

dry matter is largely diluted with water. It would be 
equally absurd to accept the dry matter in the ration as 
a standard. In instituting a comparison between bo vines 
and swine, we must remember that the former consume 
materials much less digestible than do the latter, and so a 
unit weight of food does not represent the same weight of 
available nutrients with the two classes of animals. 

We should, so far as possible, reduce rations to their 
units of nutritive value, and so the digestible dry matter 
is now the nearest approach we can make to a basis for 
comparing rations with each other or with the produc- 
tion which they sustain. It follows, then, that if we wish 
to show the comparative economy of production in dairy 
farming and in beef farming, food alone considered, we 
should express this relation on one side in terms of digesti- 
ble dry food substance.* 

508. The unit of production. — ^What shall we con- 
sider as a unit of production.?^ We may answer this 
question from two standpoints. We may measure pro- 
duction by the quantity of the commercial article which 
the farmer places on the market, or by the actual contribu- 
tion which any given production makes to the food 
resources of the human family. More specifically stated, 
we may determine the relation of a unit of digestible 
food substance to the live animal, beef, pork, milk, cheese, 
butter, or eggs resulting from its use, and calculate the 
ratio of any one of these to the actual nutrients con- 
sumed, or we may ascertain the ratio of food consump- 
tion to the edible dry substance in the various animal 

*Since the above was written, we are able to reduce the food unit 
for production to what is termed production value. This is more funda- 
mental than the digestible matter as a basis for comparison. The com- 
parisons hereafter made are, however, with the digestible matter con- 
sumed as related to the unit of production. 



420 THE FEEDING OF ANIMALS 

products. The latter is the important ratio to consider 
if we are seeking to learn how we can most efficiently 
apply farm crops to the sustenance of the human family. 

509. Factors involved in food economics. — This study 
of food economics requires a knowledge of several factors. 
In the first place, we must have the information coming 
from feeding experiments, where a careful record has 
been kept of the kind and amount of food consumed and 
the weight of the resulting growth, milk, eggs, or what not. 
This information must be supplemented by a knowledge 
of the digestibility of feeding-stuffs, of the ratio between 
the live animal or other gross product and the commer- 
cial products, and of the composition and proportion of 
edible material supplied by the commercial article. For 
instance, we find it takes, on the average, 7.4 pounds 
of digestible organic substance in the ration to produce 
1 pound of growth in a steer, and we have learned by 
slaughter tests that the average per cent of carcass for 
97 animals was 61.4, and by the butchers' and chemists' 
analyses, that the carcass contains an average of 33.2 
per cent of edible dry matter. From these data it is easy 
to calculate that 12 pounds of digestible food are needed 
for the growth of 1 pound of carcass or 36.3 pounds for 
the growth of 1 pound of edible beef solids. 

510. Relation of food to production with various 
species. — The following tables give the data upon which is 
based the productive power of food when utilized by 
the various classes of animals. Data of this kind are 
practically our only means of studying the economics 
of producing those human foods which are most costly 
in proportion to their nutritive value, a study which is 
very important wherever it becomes necessary to econo- 
mize energy. It shows the coefficients of efficiency of 



RELATION OF FOOD TO PRODUCTION 



421 



various species of animals in maintaining human life. 
The sources of all these figures are not given, for they 
are so numerous as to make this difficult. 

It is true, in general, that prices are proportional to 
the cost of production. If, therefore, natural resources 
are to be utilized for human sustenance in the most 
efficient way and the cost of living brought to the lowest 
possible point, the raw materials of the farm should be 
applied to the production of those animal foods that are 
most cheaply grown. 

The time will probably come when the relation of 
population to land areas will be such as to make necessary 
an application of food economics along this line. 

Table LXXXVIII. Production by Farm Animals. Proportions 
OF Carcass and Edible Substance 



Steers, general average 

Steers, Iowa 

Steers, Kansas . . . . 
Steers, Mainef . . . . 

Sheep 

Lambs 

Lambs, Iowa . . . . 
Swine, general average 

Pigs, Iowa 

Calves 

Fowl, large 

Fowl, small 

Chickens, broilers . . 
Eggs 



Number 

pi 
animals 



97 

5 

5 

8 

4 

44 

133 

97 

56 

23 

12 

7 

107 

34§ 



Carcass 

in per cent 

of live 

weight 



61.4 

64. 

61.4 

57.7 

50.7 

50.7 

54. 

81.2 

77.9 

57.2 

80.8 

78. 

82.lt 

88.811 



Per cent* 

of edible 

dry matter 

in carcass 



33.2 

33.2 

33.2 

32.3 

37.4 

33.7 

33.7 

62.7 

62.7 

22.2 

27. 

27. 

14.7 

26.3 



Per cent of 
edible dry 
matter in 
live animal 



20.4 

21.2 

20.4 

18.6 

19. 

17.1 

18.2 

50.9 

48.8 

12.7 

21.8 

21.1 

12.1 

23.3** 



* From Bull. No. 28, OflSce of Experiment Stations, 
t Grown from calfhood, entire bodies analyzed. 
X Not drawn. 
§ Number of samples. 
1! Per cent after removing shells. 
**In eggs with shells. 



Revised edition. 



422 



THE FEEDING OF ANIMALS 



Table LXXXIX 


. Relation of 


Food to 


Product 


■ ■' — 






Diges- 


Diges- 


Diges- 




Number 
of 




tible org. 


tible org. 


tible org. 




Number 


substance 


substance 


substance 




of 


produ- 


produ- 


Droducing 




experi- 
ments 


animals 


cing 1 lb. 


cing 1 lb. 


lib. 






increase 


increase 


increase 








hve wt. 


carcass 


edible soL 








Pounds 


Pounds 


Pounds 


Mill^", average 


61 


391 


.72 




5.55 


Milk, New York* .... 


list 


30 


.63 




4.85 


Steers, average 


32 


242 


7.4 


12. 


36.3 


Steers, la., growth 9 to 24 m. 


1 


5 


5.97 


9.33 


28.1 


Steers, Kansas, 3 years old 


1 


8 


8.08 


13.16 


39.6 


Steers, Maine 


1 


4 


6.65 


11.5 


35.7 


Sheep and lambs, average 


11 


122 


7.2 


14.2 


37.9 


Lambs, Iowa, growth while 












fattening 


2 


133 


5.63 


10.43 


30.9 


Swine, § average 


277 


1,385 


3.29 


4. 


6.4 


Pigs, Iowa 


1 


56 


3.03 


3.89 


6.2 


Calves, average 


3 


30 


1.57t 


2.7 


12.3 


Fowl, large, to 5 or 6 mos. il . 


6 




5.1 


6.3 


23.4 


Fowl, small, to 5 or 6 mos- 11 


6 




5.1 


6.5 


24.2 


Chickens, broilers, 12 wksJ 


15 




3.48** 


4.2 


28.8 


Eggsll 


14 


139tt 


4.56§§ 


5.1 


19.6 







♦Extending over seven years. 

tShort periods. 

IDeduced from compilation by Dr. Armsby for U. S. Dept. of Agriculture. 

JDry matter, mostly from milk, practically all digestible. 

llUnpubhshed data from experiments at the New York Agric. Exp. Station. 
**4.35 lbs. dry matter, assumed to be 80 per cent digestible. 
ttEgg product, 100 eggs per year. 
§§85.7 lbs. dry matter, assumed to be 80 per cent digestible. 

The figures of the foregoing tables can be regarded 
as being trustworthy for average conditions. They are 
obtained from the recorded data of experiment stations, 
and involve a large number of observations with dairy 
cows and with growing and fattening animals. 

In most cases the amount of digestible matter in the 
ration is calculated from the average coefiicients of 
digestibility. 

The facts brought out by this study of the relation 
of food to product are emphatic and suggestive. In 
order to display them as clearly as possible there are 
shown in the next table the quantities of the various 



RELATION OF FOOD TO PRODUCTION 



423 



commercial animal products, and of human food in 
animal forms, which can be produced by the use of a 
quantity of cattle food containing 100 pounds of digesti- 
ble organic matter: 



Table XC. Relation of Food to Product 



Milk, general average 

Milk, New York experiments 

Cheese, green 

Butter 

Steers, general average, live weight .... 

Steers, Iowa, live weight 

Steers, Kansas, live weight 

Steers, Maine, live weight 

Steers, general average, carcass 

^teers, Iowa, carcass 

Steers, Kansas, carcass 

Steers, Maine, carcass 

Sheep and lambs, general average, live weight 

Lambs, Iowa, live weight 

Sheep and lambs, general average, carcass 

Lambs, Iowa, carcass 

Swine, general average, Hve weight 

Swine, Iowa, live weight 

Swine, general average, carcass 

Pigs, Iowa, carcass 

Calves, Uve weight 

Calves, carcass 

Fowl, large, live weight 

Fowl, small, Uve weight 

Fowl, dressed carcass, average 

Broilers, Hve weight 

BroUers, dressed carcass 

Eggs 



Produced by 100 lbs. 

digestible organic 

matter in ration 



Marketable 
product 



Pounds 

139. 
158.7 
14.8 

6.4 
13.5 
16.8 
12.4 
15. 

8.3 
10.7 

7.6 

8.7 
13.9 
17.8 

7. 

9.6 
30.4 
33. 
25. 
25.7 
63.7 
36.5 
19.6 
19.6 
15.6 
28.7 
23.8 
19.6 



Edible 
solids 



Pounds 

18. 

20.6 
9.4 
5.44 



2.75 
3.56 
2.52 

2.84 



2.60 
3.23 



15.6 
16.1 



8.1 



4.2 

3.5 
5.1 



424 THE FEEDING OF ANIMALS 

It may properly be said of the foregoing figures that 
they are only averages and that the relation of food to 
production varies with different animals of the same class 
and with the conditions involved. While this is true, the 
relations shown in the preceding calculations represent 
differences too wide to be explained on any other ground 
than that the various animal products have greatly 
unlike food cost. 

The most noticeable fact brought out by this com- 
parison is the low relative food cost of milk and other 
dairy products. The growth of a pound of edible beef 
solids requires a food expenditure nearly seven times as 
great as is necessary for the elaboration of a pound of 
milk solids. On the other hand, swine are fed with nearly 
as great economy as are milch cows. In fact, when proper 
allowance is made for the period of growth of the cow and 
for the annual periods when she is giving no milk, she 
seems to have no advantage over the pig except in kind 
of product. Next, in the order of economical use of food, 
comes the calf when fed largely on milk. Poultry prod- 
ucts stand next in line. Sheep and lambs do not differ 
materially from steers, meat products of these two 
classes requiring the largest proportional food consump- 
tion of any form of growth here considered. The order 
of food efficiency as related to the several animal prod- 
ucts is therefore as follows: milk, pork, veal, poultry 
and eggs, mutton, and beef. 

It is suggestive, at least, to notice that the food factor 
is inversely as the labor factor in these various lines of 
production. For instance, labor is a large factor of the 
cost of a pound of any dairy product and a small factor 
in the cost of beef or mutton, while the reverse is emphati- 
cally true of the food cost. 



CHAPTER XXV 
GENERAL MANAGEMENT 

There are many considerations pertaining to the 
feeding and management of live-stock that have a more 
or less common application to all classes of animals and 
which may be discussed conveniently under one head. 
They are partly of a business character and to quite an 
extent lie outside the chemical and physiological princi- 
ples of nutrition. Some of those questions are matters 
of much importance, but many of them which relate, for 
instance, to times and methods of feeding are given a 
prominence in current discussions out of proportion to 
their real influence in determining success. It should 
be understood, too, that many of the details of practice 
are not limitable by fixed rules but must be variable 
according to the conditions involved. Tact and judgment 
are demanded of the farmer who wisely adjusts his 
practice to business principles. 

511. Factors in general management of animals. — 
General management properly includes, among other 
considerations, the following topics: 

(1) The selection of animals; (2) manipulation of 
the ration and manner of feeding; (3) the intensity of 
feeding; (4) environment and treatment of the animal. 

The object to be sought in feeding animals is the con- 
version of a unit of food into the largest possible quan- 
tity of the product best adapted to the producer's com- 
mercial opportunities, and here the limitations of the 

(425) 



426 THE FEEDING OF ANIMALS 

animal are often the limitation of the farmer's profits. 
Within each species varietal and individual differences 
determine the rate of production and also whether the 
food shall be transformed into poor milk or rich milk, 
inferior beef and mutton or superior meat products, fine 
wool or coarse, trotters or draft horses, and small eggs or 
large ones. 

The selection of animals should have reference to 
three general factors, which largely fix the rate and 
character of production, viz., breed, individuality, and 
age. 

512. The selection of cows. — ^The breed and indi- 
viduality of the cow largely determine the quality of her 
product and the quantity of production from a unit of 
food. Neither heavy feeding nor skill in compounding 
rations can be made the means of causing her to overstep 
her constitutional limitations. 

The selection of cows simply with reference to breed 
is a question of adaptability. If the production of milk 
at the minimum food cost for a unit of volume is the 
result most desired, the dairy breeds, characterized by 
milk with a low proportion of solids should be chosen; 
but if the object is merely to secure butter-fat with the 
lowest possible food expenditure, the so-called butter 
breeds are in general to be preferred. 

When the chief consideration is the manufacture of 
milk solids most economically, we must deal not so much 
with breeds as with individuals. In fact, with all breeds 
and with animals of no breed, individual capacity is the 
consideration fundamental to profitable feeding. Some 
Holsteins will return both more milk and more butter 
for a unit of food cost than will some Jerseys, and the 
reverse is equally true. There is no magic in heredity 



GENERAL MANAGEMENT 427 

which overcomes lack of capacity either for the breeder 
or for the dair^Tnan. 

513. The general-purpose cow. — ^The "general-pur- 
pose" cow has been much discussed in recent years. 
While her specifications have never been fully and clearly 
set forth, it is supposed that she is an animal reasonably 
profitable along both beef and milk lines. It is doubtful 
whether such a cow, even if she exists, is one adapted to 
general utility. There are few localities where milk is 
not more profitable than beef or beef more profitable 
than milk, and whichever is the more profitable should 
be produced by an animal of specialized capacity. Any 
extra value which the calf's or the cow's carcass may have 
when flesh-forming tendencies are prominent, will gen- 
erally come far short of compensating for a merely medi- 
ocre milk yield in those localities where there is a market 
for milk and its products; and the stockman who is 
endeavoring to put on the market beef animals of the 
highest quality cannot afford to compromise with dairy 
qualities. Milk formation and flesh formation are antag- 
onistic, and not correlated, functions, both of which do 
not operate intensely in the same individual. At present 
we have no breed or fixed type of animals that can be 
regarded as presenting and perpetuating "general-pur- 
pose" qualities. Such a type, if found at all, must be 
sought among individuals. 

514. The selection of animals for meat production. — 
It is generally conceded that the selection of breeds of the 
beef and mutton types is essential to the highest success 
in the production of meat. This is true with steers, not 
because those from the dairy breeds will make very 
much slower growth than Shorthorns or Herefords, for 
this does not seem to be the fact, but because the quality 



428 THE FEEDING OF ANIMALS 

of the product is higher with the latter, that is, the pro- 
portion of valuable parts is greater and the distribution of • 
fat and lean tissue is more desirable, in the distinctly 
beef animal. 

A choice from the beef and mutton types and from 
the various breeds of swine may safely be left to personal 
preference. Many experiments have been conducted 
with a view of determining the relative capacity of 
growth of the prominent breeds of bovines, sheep, 
and swine, and the testimony so far adduced is of a 
negative character and does not point to any one 
breed of any species as clearly superior to all others. 
It is well understood, however, that within every 
breed individual variations are important and that 
from a * 'bunch*' of steers it is possible to select some 
animals superior to the others in their capacity to make 
profitable use of food. 

515. Relation of age to meat production. — ^A most 
important factor in this connection is the relation of age 
to the profits of meat production. Nothing has been more 
fully established by experimental evidence than that the 
younger the animals the larger the ratio of increase to 
body weight and the greater the increase for each unit of 
food consumed. 

Some of the more striking evidence on these points 
is presented in the following figures : 

Table XCI 

Results with steers from five breeds slaughtered at the Smithfield 
{England) Fat-Stock Show {from Henry's compilation) 
Age Number animals Daily gain 

One year old 77 2. lbs. 

Two years old 89 1.76 " 

Three years old 54 1.58 " 



GENERAL MANAGEMENT 



429 



Table XCI, continued 

Steers at American Fat-Stock Show {StewarVs compilation) 

Age Number animals Daily gain 

297 days 30 2.6 lbs. 

612 " 152 2.2 " 

943 '' 145 1.7 " 

1,283 " 133 1.5 " 

American exyerim^nts with pigs {Henry's compilation) 
Weight of pigs Number feeding trials Food for 100 lbs. gain 



38 lbs. 41 




293 lbs. 


78 " 100 




400 " 


128 " 119 




437 " 


174 " 107 




482 " 


227 " 72 




498 " 


271 " 46 




511 '' 


320 " 19 




535 " 


Results of Danish experiments with 


pigs. 




Weight of pigs Number experiments 


Food for 100 lbs. gain 


35 to 75 lbs. 3 




376 lbs. 


75 to 115 " 10 




435 " 


115 to 135 " 13 




466 " 


155 to 195 " 15 




513 " 


195 to 235 " 14 




540 " 


235 to 275 " 11 




614 " 


275 to 315 " 3 




639 " 



Testimony of this character is abundant, and the lesson 
for practice is that animals should be fed for market at 
the earliest age that is consistent with other conditions. 

516. Manipulation of the ration. — ^A great deal of 
experiment and discussion has been devoted to the 
economy of various methods of treating cattle foods, 
such as cutting, grinding, wetting, and cooking. The 
economy of these operations requires no extended com- 
ment. It is a simple and safe rule that any fodder or 
grain, that in its natural condition is palatable, is wholly 
eaten, and is thoroughly masticated, should be fed with- 



430 THE FEEDING OF ANIMALS 

out the unnecessary expense which these manipulations 
would cause. Grinding any material that is not otherwise 
thoroughly masticated doubtless increases the efficiency 
of the food, but when the grinding costs as much as 10 
per cent of the market price of the grain it is doubtful 
if any advantage accrues. Cutting, unless for the pur- 
pose of mixing, has the sole advantage of saving the animal 
a little work. 

Wetting and cooking render certain foods more 
tender and more palatable, and when this secures the 
consumption of materials otherwise wasted these opera- 
tions may become economical. On the contrary, similar 
treatment of grain foods already much liked by the 
animal is, according to the majority of testimony, an 
occasion of loss rather than of gain. 

Practice differs as to the number of portions into 
which the daily ration shall be divided. Some herds 
are fed three times a day and some twice. While it 
would be possible to feed too many times or too much 
at any one time, it seems more than probable that if 
animals are fed regularly the ration may be as efficient 
when divided into two portions as when there are three 
feeding periods. The adaptation of any system to the 
requirements of farm work is a matter of more impor- 
tance, probably, than any influences proceeding from the 
number of feeding-periods. The warming of the water 
consumed has been introduced to some extent with dairy 
herds. Certainly it is bad practice to force cows to drink 
ice-cold water, but it is also bad practice to warm the 
water above the point of palatableness. The likes and 
dislikes of animals must be considered, and to ignore them, 
even to save the small food expense necessary for warm- 
ing the ingested water, is not advisable. 



GENERAL MANAGEMENT 431 

517. Quantity of the ration. — Great stress is usually 
laid upon the fact that it is only the food that is supplied 
above maintenance needs which is productive. This 
truth, indiscriminately accepted, has led to feeding 
so excessively as to injure the health of the animals and 
diminish profits. The largest production is not always 
the most profitable. Abundant testimony can be cited 
in support of the statement that very heavy rations 
yield smaller returns for each unit of food consumed 
than more moderate ones. It is possible, also, to adopt 
an unprofitable extreme in the direction of light feeding. 
Heavy rations are sometimes warranted by the low 
cost of feeds and the high price of the resulting product, 
a condition which has not existed for the past ten 
years. In the writer's judgment, milk is more economically 
produced by cows not unusual in character or size when 
the grain ration, wisely compounded, ranges between 
eight and ten pounds daily, according to the weight 
and capacity of the animal, than when more is fed, pro- 
vided the coarse foods are supplied in the ordinary propor- 
tion. It is especially important with breeding animals, 
where the physical condition of the dam should be kept 
at its best, that the indigestion and high physical tension 
induced by extreme rations should be avoided. The wel- 
fare of future generations demands this. 

518. Environment and treatment of animals. — ^The 
quarters in which animals live should be comfortable, 
that is, they should be neither too warm nor too cold and 
should be well ventilated. These conditions are essential 
to health and the most profitable production. The 
stable temperature in winter should be held above 45° F. 
as a minimum, and may well be kept below 60°. A con- 
stant exchange of air should be secured without creating 



432 THE FEEDING OF ANIMALS 

cold drafts, and the "King" system of ventilation seems 
to be worthy of commendation. 

All domestic animals, whether the milch cow or the 
fattening steer, should have a reasonable amomit of 
exercise under comfortable conditions. Little sym- 
pathy should be shown toward the modern fad of tying 
cows by their heads in one spot for five or six months, 
under the plea that exercise is work and work costs food. 
The statement had better be in accordance with the 
experience of all time, that exercise is health and vigor 
and that food is well used in maintaining these. The cow 
is more than a machine; she is a sentient being, suscepti- 
ble to many of the influences which are essential to the 
physical welfare of the human species. Let no one take 
this opinion as an excuse for the cruel and wasteful expo- 
sure of farm animals to inclement weather, which is so 
often observed, for this is simply a violation of the laws 
of kindness and economy in the other direction. 

A sympathetic relation should be established between 
the animal and the herdsman. Close observers declare 
that such a relation promotes greater thrift and larger 
production, especially with dairy cows. These animals, 
possessed of the instincts and affections of motherhood, 
respond to fondling through its influence upon their 
nervous organization. 

Moreover, the economic relation is not the only one 
man sustains to the animal world. Farm animals are 
man's companions and friends for which he may enter- 
tain even sentiments of affection. The daily life of the 
farm-house is full of pleasant experiences that belong to 
the care of, and association with, the grateful creatures 
whose wants must be supplied — the motherly cow, the 
faithful horse, or the noisy, cackling fowl. No farmer 



GENERAL MANAGEMENT 433 

has reached his best estate who does not find in the 
animal Hfe about him an enjoyable companionship of 
which he need not be ashamed, and without a sense of 
which he is not prepared to fulfil his obligations to the 
creatures dependent upon him. 

519. Cruelty to animals. — While it is the purpose of 
this volume to deal with the facts and principles of 
science and practice, it is not improper briefly to urge 
the need of the cultivation of right sentiment concerning 
kindness in the care of animals, for we really do not fully 
appreciate the imkindness showTi by man toward the 
inferior species under his control. In no way has he more 
clearly demonstrated that he partakes of the brute 
natm-e than in his treatment of the brute. As a master 
he has been guilty of cruelty which it is humiliating to 
contemplate, a cruelty not so swift in its operation as 
that of the beast of prey, but which is greatly more 
shocking and is wholly at variance with the exalted 
characteristics that we attribute to humanity. The half- 
sheltered animals that have endured our cold northern 
winters — the spavined, wind-broken wrecks of our livery 
stables, whose infirmities secure for them no relief from 
hard service — the daily exhibitions on our city streets of 
the patient draft horse with raw flesh under the collar 
and smarting under blows from unfeeling, cursing drivers 
— and especially the deliberately brutal practices of the 
race-track, where amid the plaudits of a throng of men 
and women w^ho would claim to have kind hearts, noble 
animals, by imjustifiable "scoring" and in the subse- 
quent race, are often forced to the last limits of endurance 
— these are all evidences of an utterly selfish indifter- 
ence to the suffering of living creatures that can neither 
utter a complaint nor avenge their wrongs. A certain 

BB 



434 THE FEEDING OF ANIMALS 

proportion of humanity appears to regard the animal 
as a mere unfeeHng machine out of which pleasure and 
gain are to be forced even to the pound of flesh, and 
not as sentient beings capable of the keenest physical 
pain and with rights that should be respected. The 
constant occurrence of the ill-treatment of animals is 
perhaps the cause of the complaisance with which it is 
regarded, but it is no excuse for such thoughtless 
indifference. Society notes and punishes flagrant cases 
of abuse, but the average human conscience is not yet 
sufficiently tender toward man's treatment of his faith- 
ful servants. 



APPENDIX 

COMPOSITION, DIGESTION, AND FEEDING 
STANDARDS BY TABLES 

1. Average composition of American feeding-stuffs, page 435. 

2. Average coefficients of digestion, page 441. 

3. Energy-production values of feeding-stuffs, page 448. 

4. Food standards for milk production as developed by Haecker, 

Savage, and Eckles, page 455. 

5. Feeding standards, page 457. 

6. Fertilizing constituents of American feeding-stuffs, page 460. 

1. AVERAGE COMPOSITION OF AMERICAN FEEDING- 
STUFFS 

The figures in the following table have been taken 
from Bulletin No. 11, Office of Experiment Stations; 
Farmers' Bulletin No. 22, United States Department of 
A.gricultiu"e; Bulletin No. 81, Vermont Agricultural 
Experiment Station, and Bulletin No. 166, New York 
Agricultural Experiment Station (Geneva). 

The percentages given represent averages from which 
there are material variations. These variations are 
mostly due to differences in the water-content, the in- 
fluence of locality and of the stage of growth and the 
changes brought about by the methods and conditions 
of curing. They are not so large and important with 
the grains as with the fodders. 

A more complete table of the composition of feeding- 
stuffs is to be found in Henry & Morrison's "Feeds and 
Feedings," the edition of 1915. The figures given in the 

(435) 



436 



APPENDIX 



following tables, however, are sufficiently full and accu- 
rate to illustrate the composition of the various classes 
of feeds. 

Composition of Feeding-Stuffs 

Nitrogen- No. of 

free analy- 

Water Ash Protein Fiber extract Fat ses 

^ , ,^ % % % % % % 
Green fodder 

Com fodder — * 

Flint varieties 79.8 1.1 2. 4.3 12.1 .7 40 

Flint varieties cut 
after kernels had 

glazed 77.1 1.1 2.1 4.3 14.6 .8 10 

Dent varieties 79. 1.2 1.7 5.6 12. .5 63 

Dent varieties cut 
after kernels yhad 

glazed 73.4 1.5 2. 6.7 15.5 .9 7 

Sweet varieties 79.1 1.3 1.9 4.4 12.8 .5 21 

All varieties 79.3 1.2 1.8 5. 12.2 .5 126 

Leaves and husks, 

cut green 66.2 2.9 2.1 8.7 19. 1.1 4 

Stripped stalks, cut 

green 76.1 .7 .5 7.3 14.9 .5 4 

Sorghum fodder 79.4 1.1 1.3 6.1 11.6 .5 11 

Rye fodder 76.6 1.8 2.6 11.6 6.8 .6 7 

Barley fodder 79. 1.8 2.7 7.9 8. .6 1 

Oat fodder 62.2 2.5 3.4 11.2 19.3 1.4 6 

Pasture grass 80. 2. 3.5 4. 9.7 .8 

Red-top,t in bloom 65.3 2.3 2.8 11. 17.7 .9 5 

Tall oat gr a s s,t in 

bloom 69.5 2. 2.4 9.4 15.8 .9 3 

Orchard grass, in 

bloom 73. 2. 2.6 8.2 13.3 .9 4 

Meadow fescue, in 

bloom 69.9 1.8 2.4 10.8 14.3 .8 4 

Italian rj'^e grass, com- 
ing into bloom 73.2 2.5 3.1 6.8 13.3 1.3 24 

Timothy, § at different 

stages 61.6 2.1 3.1 11.8 20.2 1.2 56 

Kentucky blue-grass,** 

at different stages. .. . 65.1 2.8 4.1 9.1 17.6 1.3 18 

Hungarian grass 71.1 1.7 3.1 9.2 14.2 .7 14 

Japanese miUet 75. 1.5 2.1 7.8 13.1 .5 12 

*Corn fodder is the entire plant, xisually a thickly planted crop. Corn stover 
is what is left after the ears are harvested. 

tHerd's grass of Pennsylvania. J Meadow oat grass. 

§Herd'8 grass of New England and New York. **June Grass. 



COMPOSITION OF FEEDING-STUFFS 



437 



Water 

% 

Green Fodder — continued 

Red clover, at different 

stages 70.8 

Alsike clover,* in bloom. 74.8 

Crimson clover 80.9 

Alfalfa.t at different 

stages 71.8 

Serradella, at different 

stages 79.5 

Cowpea 83.6 

Soja bean 75.1 

Horse bean 84.2 

Flat pea (Lathynis 

sylvestris) 66.7 

Rape 84.5 



Silage 

Com silage 

Sorghum silage 

Red-clover silage 

Soja-bean silage 

Cowpea-\'ine silage 

Field-pea- vine silage. . . . 

Silage of mixture of 
cowpea vines and 
soja-bean vines. 

Millet and soja bean 

Com and soja bean. 

Rye 

Apple pomace 



79.1 
76.1 
72. 

74.2 
79.3 
50.1 



69.8 

79. 

76. 

80.8 

85. 



Hay and Dry Coarse Fodder 
Com fodder,t field-cured . 42.2 
Com leaves, field-cured. 
Com husks, field-cured. 
Com stalks, field-cured . 
Com stover § field-cured 
Barley hay, cut in milk. 
Oat hay, cut in milk. . . 
Hay from — 

Red- top,** cut at dif- 
ferent stages 

Red-top, cut in bloom 
Orchard grass 

♦Swedish clover. 
tLucerne. 
JEntire plant. 



30. 

50.9 

68.4 

40.5 

15. 

15. 



8.9 
8.7 
9.9 



Ash 
% 



2.1 

2. 
1.7 



3.2 

1.7 
2.6 
1.2 

2.9 
2. 



1.4 
1.1 
2.6 
2.8 
2.9 
3.5 



4.5 
2.8 
2.4 
1.6 
.6 



5.5 
1.8 
1.2 
3.4 
4.2 
5.2 



Protein 
% 



4.4 
3.9 
3.1 



2.7 4.8 



2.7 
2.4 
4. 
2.8 

8.7 
2.3 



1.7 

.8 

4.2 

4.1 

2.7 
5.9 



3.8 
2.8 
2.5 
2.4 
1.2 



6. 
2.5 
1.9 
3.8 

8.8 
93 



Fiber 
% 



8.1 
7.4 
5.2 



Nitrogen- 
free 
extract 

% 



13.5 
11. 

8.4 



5.4 
4.8 
6.7 
4.9 

7.9 
2.6 



6. 
6.4 
8.4 
9.7 
6. 
13. 



9.5 
7.2 

7.2 
5.8 
3.3 



21.4 

15.8 

11. 

19.7 

24.7 

29.2 



8.6 

7.1 

10.6 

6.5 

12.2 
8.4 



11. 

15.3 

11.6 
6.9 
7.6 

26. 



11.1 

7.2 

11.1 

9.2 

8.8 



35.7 

28.3 

17. 

31.5 

44.9 

39. 



Fat 
% 



1.1 
.9 

.7 



7.4 12.3 1. 



.7 
.4 



1. 



1.6 
.5 



.3 
1.2 
2.2 
1.5 
1.6 



1.3 

1. 
.8 
.3 

1.1 



2.7 4.5 14.3 34.7 1.6 



1.4 
.7 
.5 
1.1 
2.4 
2.3 



No. of 
analy- 
ses 



43 
4 
3 

23 

9 
10 
27 

9 



99 
6 
5 
1 
2 
1 



6o 
17 
16 

15 

60 

1 

1 



5.2 7.9 28.6 47.5 1.9 9 

4.9 8. 29.9 46.4 2.1 3 

6. 8.1 32.4 41. 2.6 10 

§What is left after the ears are harvested. 
**Herd's grass of Pennsylvania. 



438 



APPENDIX 



Water Ash Protein 

Hay and Dry Coarse Fodder 7<i 7o 7q 

— continued 
Hay from — 

Timothy * all analy's. 13.2 4.4 5.9 
Timothy, cut in full 

bloom 15. 4.5 6. 

Timothy, cut soon af- 
ter bloom 14.2 4.4 5.7 

Timothy, cut when 

nearly ripe 14.1 3.9 5. 

Kentucky blue-grass.. 21.2 6.3 7.8 
Cut when seed was 

in milk 24.4 7. 6.3 

Cut when seed was 

ripe 27.8 6.4 5.8 

Hungarian grass 7.7 6. 7.5 

Meadow fescue 20. 6.8 7. 

Italian rye grass 8.5 6.9 7.5 

Perennial rye grass. . . 14. 7.9 10.1 

Mixed grasses 15.3 5.5 7.4 

Rowen (mixed )t 16.6 6.8 11.6 

Mixed grasses and 

clovers 12.9 5.5 10.1 

Swamp hay 11.6 6.7 7.2 

Salt marsh 10.4 7.7 5.5 

Red clover 15.3 6.2 12.3 

Red clover in bloom.. 20.8 6.6 12.4 

Alsike clover 9.7 8.3 12.8 

White clover 9.7 8.3 15.7 

Crimson clover 9.6 8.6 15.2 

Japan clover 11. 8.5 13.8 

Vetch 11.3 7.9 17. 

Serradella 9.2 7.2 15.2 

Alfalfat 8.4 7.4 14.3 

Cowpea 10.7 7.5 16.6 

Soja bean 11.3 7.2 15.4 

Flat pea {Lathyrus 

sylvestris) 8.4 7.9 22.9 

Peanut vines (with- 
out nuts) 7.6 10.8 10.7 

Pea vines 15. 6.7 13.7 

Soja-bean straw 10.1 5.8 4.6 

Horse-bean straw 9.2 8.7 8.8 

Wheat straw 9.6 4.2 3.4 

Rye straw 7.1 3.2 3. 

Oat straw 9.2 5.1 4. 

Buckwheat straw 9.9 5.5 5.2 

*Herd's grass'of New England and New York. 



Fiber 


Nitrogen- 
free 
extract 


Fat 


No. of 
analy- 
ses 


% 


% 


% 




29. 


45. 


2.5 


68 


29.6 


41.9 


3. 


12 


28.1 


44.6 


3. 


11 


31.1 


43.7 


2.2 


12 


23. 


37.8 


3.9 


10 


24.5 


34.2 


3.6 


4 


23.8 


33.2 


3. 


4 


27.7 


49. 


2.1 


13 


25.9 


38.4 


2.7 


9 


30.5 


45. 


1.7 


4 


25.4 


40.5 


1.7 


4 


27.2 


42.1 


2.5 


126 


22.5 


39.4 


3.1 


23 


27.6 


41.3 


2.6 


17 


26.6 


45.9 


2. 


8 


30. 


44.1 


2.4 


10 


24.8 


38.1 


3.3 


38 


21.9 


33.8 


4.5 


6 


25.6 


40.7 


2.9 


9 


24.1 


39.3 


2.9 


7 


27.2 


36.6 


2.8 


7 


24. 


39. 


3.7 


2 


25.4 


36.1 


2.3 


5 


21.6 


44.2 


2.6 


3 


25. 


42.7 


2.2 


21 


20.1 


-42.2 


2.2 


8 


22.3 


38.6 


5.2 


6 


26.2 


31.4 


3.2 


5 


23.6 


42.7 


4.6 


6 


24.7 


37.6 


2.3 


1 


40.4 


37.4 


1.7 


4 


37.6 


34.3 


1.4 


1 


38.1 


43.4 


1.3 


7 


38.9 


46.6 


1.2 


7 


37. 


42.4 


2.3 


12 


43. 


35.1 


1.3 


3 


tSecond cut. 


J Lucerne. 



COMPOSITION OF FEEDING-STUFFS 



439 



Water 

% 
Roots and Tubers 

Potatoes 78.9 

Sweet potatoes 71.1 

Red beets 88.5 

Sugar-beets 86.5 

Mangel-wurzels 90.9 

Turnips 90.5 

Rutabagas 88.6 

Carrots 88.6 

Artichokes 79.5 



Ash 


Protein 


Fiber 


Nitrogen- 
free 
extract 


Fat 


No. of 
analy- 
ses 


% 


% 


% 


% 


% 




1. 


2.1 


.6 


17.3 


.1 


12 


1. 


1.5 


1.3 


24.7 


.4 


6 


1. 


1.5 


.9 


8. 


.1 


9 


.9 


1.8 


.9 


9.8 


.1 


19 


1.1 


1.4 


.9 


5.5 


.2 


9 


.8 


1.1 


1.2 


6.2 


.2 


3 


1.2 


1.2 


1.3 


7.5 


.2 


4 


1. 


1.1 


1.3 


7.6 


.4 


8 


1. 


2.6 


.8 


15.9 


.2 


2 



Grains and Other Seeds 

Com kernel — 

Dent, all analyses. . . . 10.6 

Flint, all analyses. ... 11.3 

Sweet, all analyses. . . 8.8 

Pop varieties 10.7 

Soft varieties 9.3 

All varieties and 

analyses 10.9 

Sorghum seed 12.8 

Barley 10.9 

Oats 11. 

Rye 11.6 

Wheat — 

Spring varieties 10.4 

Winter varieties, all 

analyses 10.5 

All varieties 10.5 

Rice 12.4 

Buckwheat 12.6 

Sunflower seed (whole). 8.6 

Flaxseed 9.2 

Cottonseed (whole, with 

hulls) 10.3 

Cottonseed kernels 

(without hulls) 6.2 

Cottonseed whole, 

roasted 6.1 

Peanut kernels (with- 
out hulls) 7.5 

Horse bean 11.3 

Soja bean 10.8 

Cowpea 14.8 



1.5 


10.3 


2.2 


70.4 


5. 


86 


1.4 


10.5 


1.7 


70.1 


5. 


68 


1.9 


11.6 


2.8 


66.8 


8.1 


26 


1.5 


11.2 


1.8 


69.6 


5.2 


4 


1.6 


11.4 


2. 


70.2 


5.5 


5 


1.5 


10.5 


2.1 


69.6 


5.4 


208 


2.1 


9.1 


2.6 


69.8 


3.6 


10 


2.4 


12.4 


2.7 


69.8 


1.8 


10 


3. 


11.8 


9.5 


59.7 


5. 


30 


1.9 


10.6 


1.7 


72.5 


1.7 


6 


1.9 


12.5 


1.8 


71.2 


2.2 


13 


1.8 


11.8 


1.8 


72. 


2.1 


262 


1.8 


11.9 


1.8 


71.9 


2.1 


310 


.4 


7.4 


.2 


79.2 


.4 


10 


2. 


10. 


8.7 


64.5 


2.2 


8 


2.6 


16.3 


29.9 


21.4 


21.2 


2 


4.3 


22.6 


7.1 


23.2 


33.7 


50 


3.5 


18.4 


23.2 


24.7 


19.9 


5 


4.7 


31.2 


3.7 


17.6 


36.6 


2 


5.5 


16.8 


20.4 


23.5 


27.7 


2 


2.4 


27.9 


7. 


15.6 


39.6 


7 


3.8 


26.6 


7.2 


50.1 


1. 


1 


4.7 


34. 


4.8 


28.8 


16.9 


8 


3.2 


20.8 


4.1 


55.7 


1.4 


5 



440 



APPENDIX 



Nitrogen- 
free 
Fiber extract 

% % 



5.7 64.2 4.4 



Water Ash Protein 

% % % 
MUX Products 

Com meal 15. 1.4 9.2 1.9 68.7 3.8 

Com-and-cob meal 15.1 1.5 8.5 6.6 64.8 3.5 

Oatmeal 7.9 2. 14.7 .9 67.4 7.1 

Barley meal 11.9 2.6 10.5 6.5 66.3 2.2 

Rye flour 13.1 .7 6.7 .4 78.3 .8 

Wheat flour, all analyses 12.4 .5 10.8 .2 75. 1.1 

Buckwheat flour 14.6 1. 6.9 .3 75.8. 1.4 

Ground linseed 8.1 4.7 21.6 7.3 27.9 30.4 

Pea meal 10.5 2.6 20.2 14.4 51.1 1.2 

Soja-bean meal 10.8 4.5 36.7 4.5 27.3 16.2 

Ground com and oats, 

equal parts 13. 2.2 10.5 

Waste Products 

Com cobs 10.7 1.4 2.4 30.1 

Hominy chops 11.1 2.5 9.8 3.8 

Com bran 9.1 1.3 9. 12.7 

Com gerai 10.7 4. 9.8 4.1 

Com-gerai meal 8.1 1.3 11.1 9.9 

Gluten meal — 

Cream 10.1 .8 33.7 1.7 

Chicago* 12.3 1.3 36.5 1.4 

King 7.4 .5 33.7 1.2 

Gluten feed 7.8 1.1 24. 5.3 

Buffalo* 9.6 2.3 27.1 6.7 

Peoria* 7.5 .8 19.8 8.2 

Diamond, or Rock- 
ford 8.9 

Chicago maize feed 9.1 

Glucose feed and glu- 
cose refuse 6.5 1.1 20.7 

Dried starch feed and 

sugar feed 10.9 .9 19.7 4.7 54.8 9. 

Starch feed, wet 65.4 .3 6.1 3.1 22. 3.1 

Oat hulls 7.3 6.7 3.3 29.7 52.1 1. 

Oat feed. . . : 7.7 3.7 16. 6.1 59.4 7.1 

Barley screenings 12.2 3.6 12.3 7.3 61.8 2.8 

Maltsprouts 5. 6.4 27.6 10.9 47.1 3. 

Brewers' grains, wet . . . 75.7 1. 5.4 3.8 12.5 1.6 

Brewers' grains, dried . 8.2 3.6 19.9 11. 51.7 5.6 

Grano gluten 5.8 2.8 31.1 12. 33.4 14.9 

Rye bran 11.6 3.6 14.7 3.5 63.8 2.8 

Rye shorts 9.3 5.9 18. 5.1 59.9 2.8 

Wheat bran from spring 

wheat 11.5 5.4 16.1 8. 54.5 4.5 

*Included in above average. 



No. of 
analy- 

Fat 868 

% 



.8 23.6 6.6 
.9 22.8 7.6 



54.9 

64.5 

62.2 

64. 

62.5 

51.1 
45.8 
52.6 
51.2 
51.1 
51.1 

56.6 
52.7 



.5 

8.3 
5.8 
7.4 
7.1 

2.6 

2.7 
4.6 

10.6 
3.2 

12.6 

3.5 
6.9 



4.5 56.8 10.4 



77 
7 
6 
3 
4 

20 
4 
2 
2 
1 



18 

12 

5 

3 

6 



11 
1 



4 
12 

4 
2 

15 
3 
1 

7 
1 

10 



COEFFICIENTS OF DIGESTION 441 



Ash 


Protein 


Fiber 


Nitrogen- 
free 
extract 


Fat 


No. of 
analy- 
ses 


% 


% 


% 


% 


% 




5.9 


16. 


8.1 


53.7 


4. 


7 


5.8 


15.4 


9. 


53.9 


4. 


88 


3.8 


17.4 


5.2 


58. 


5.6 


. . 


4.6 


14.9 


7.4 


56.8 


4.5 


12 


2.9 


12.5 


4.9 


65.1 


3. 


10 


10. 


12.1 


9.5 


49.9 


8.8 


5 


13.2 


3.6 


35.7 


38.6 


.7 


3 


6.7 


11.7 


6.3 


58. 


7.3 


4 


2.2 


4.6 


43.5 


35.3 


1.1 


2 


3. 


12.4 


31.9 


38.8 


3.3 


2 


4.8 


28.9 


4.1 


41.9 


7.1 


3 


6.2 


45.6 


5.4 


25.2 


10.8 


. 


2.8 


4.2 


46.3 


33.4 


2.2 


20 


5.3 


35.7 


7.5 


36. 


7.2 




5.2 


36.1 


8.4 


36.7 


3.6 


, , 


4.9 


47.6 


5.1 


23.7 


8. 


2,480 


3.4 


6.6 


64.3 


15.1 


1.6 


5 


1. 


2.5 


4.4 


34.8 


1.9 




.4 


.7 


1.2 


16.6 


.4 


. . 


.5 


1.4 


3.9 


16.2 


1.3 


7 


.6 


.9 


2.4 


6.3 


. , 


16 


10.6 


9.1 


, , 


59.5 


. . 


35 


1.4 


2.4 


1.5 


3.9 


.4 


2 


2.2 


2.4 


1.6 


5.1 


.3 


41 


.5 


1.3 


1.7 


5.2 


.4 


, , 


2.4 


2.6 


2.2 


4.4 


.4 


. . 



Water 

% 
Waste Products — continued 

Wheat bran from winter 

wheat 12.3 

Wheat bran, all analyses 11.9 

Wheat middlings 10. 

Wheat shorts 11-8 

Wheat screenings 11-6 

Rice bran 9.7 

Rice hulls 8.2 

Rice polish 10. 

Buckwheat hulls 13.2 

Buckwheat bran 10.5 

Buckwheat middlings.. . 13.2 

Cottonseed meal 6.8 

Cottonseed hulls 11.1 

Lins'd meal, old proc's. 8.3 

Lins'd meal, new proc's 10. 

Peanut meal 10.7 

Peanut hulls 9. 

Miscellaneous 

Acorns 55.3 

Apples 80.8 

Apple pomace 76.7 

Beet pulp 89.8 

Beet molasses 20.8 

Cabbage 90.5 

Prickly comfrey 88.4 

Pumpkin (field) 90.9 

Sugar-beet leaves 88. 



2. AVERAGE COEFFICIENTS OF DIGESTION 

The coefficients of digestion which follow are mostly 
taken from the compilation by Jordan and Hall as pub- 
lished in Bulletin No. 77, Office of Experiment Stations. 
Others, marked G, are from the compilation of Dietrich 
and Konig ("Composition and Digestibility of Cattle 
Foods," Vol. II). Later figures are found in Report of 
Hatch Experiment Station, Massachusetts, 1905, and in 
Henry & Morrison's "Feeds and Feeding," 1915. 



442 



APPENDIX 



Digestion by Ruminants 

, Digestion coefficients > 

Nitrogen- 
No. ex- Kind and condi- Dry Organic Pro- free ex- 
perim'ts tion of food matter matter Ash tein Fiber tract Fat 

% % % % % % % 
Gbeen Fodders 

Meadow Grasses 

3 . Hungarian 67.2 68.6 52.2 64.3 71.2 67.9 65.7 

4 . Barnyard millet 66.6 67. 59.5 61.5 66.5 68.3 64.3 

1 . Timothy 63.5 65.6 32.2 48.1 55.6 65.7 53.1 

1 . Timothy rowen 64.8 66.4 45.2 71.7 63.8 67.8 52.9 

1 . Pasture grass 68.7 70. 49.7 65.5 74.3 72.5 54.7 

1 . Mixed-grass rowen 65.6 67.4 46.2 67.4 62.6 71.6 55.2 

Cereal Plants 

2 . Barley 65.9 67.5 54.4 71.8 60.8 71.2 59.9 

8. Dent corn, immature. . 68.8 70.7 45.4 65.2 66.6 73. 72. 

6 . Dent com, mature 66.6 68.5 19.4 52.3 51.6 74.7 77. 

14 . Dent com, all samples.. 67.8 69.8 35.6 59.7 60.2 73.7 74.1 

6. Sweet corn 71.1 72.2 55.3 64. 62.9 76.6 75.6 

3 . Oats 59.5 60.9 53.4 71.8 52.8 62.6 69.2 

1 . Rye 73.4 75.3 55.8 79.4 79.2 70.1 74.5 

2 . Sorghum 67.3 69. 42.4 46.8 59. 74.6 74.2 

Clovers and Legumes 

6. Alfalfa (G) 64. ..81. 41. 72. 45. 

1 . Crunson clover 67.9 69.1 56.1 77.1 56.1 74.5 66.5 

1 . Red clover 66.1 68.1 55. 67. 52.6 77.6 64.5 

1 . Red clover, before 

bloom (G) 74. . . 74. 60. 83. 65. 

2 . Red clover, beginning 

bloom (G) 71. .. 74. 57. 79. 71. 

2 . Red clover, bloom to 

end (G) 61. .. 64. 44. 71. 53. 

1 Red-clover rowen 59.3 60.8 43.4 61.9 52.5 65.3 60.8 

1 . Canada peas 68.4 71.3 42.3 82. 62.4 71. 52.4 

2 Cowpea 68.3 74.1 22.8 75.6 59.6 80.6 59.4 

4 Soybean 59.8 64.5 18.9 75.1 47. 73.2 54.1 

1 . Common vetch 61.8 65.7 17.3 71.4 44.2 76.1 58.6 

3. Hairy vetch 70.3 73.1 45.1 82.8 61.1 76.3 71.6 

Mixed 

1 . Barley and peas 53.4 60.2 46.2 77.2 43.5 61.4 59.7 

4 . Oats and peas 65.4 67.2 45.4 76.1 59.7 67.7 67.7 

1 . Vetch and oats 67. 68.4 52.7 74.8 68.3 67.9 47.2 



COEFFICIENTS OF DIGESTION 443 

/ Digestion coefficients > 

Nitrogen- 
No. ex- Kind and condi- Dry Organic Pro- free ex- 
perim'ts tion of food matter matter Ash tein Fiber tract Fat 

% % % % % % % 
Silage 

Maize 

9. Dent com 65.1 67.1 32.2 49.3 66.7 68.6 80. 

6. Flint corn 73.1 76.1 32.9 62.8 75.1 76.9 81.8 

13 . Dent com, immature. . 65.6 67.4 34.3 51.3 70.6 67.4 80.2 
10 . Dent and flint com, 

mature 70.8 73.6 30.3 56. 70. 76.1 82.4 

1. Sweet com 68.1 70.1 31.9 54. 71.1 71.8 83.5 

Miscellaneous 

1 . Cowpea 59.6 63.4 30.3 57.5 52. 72.5 62.6 

1 . Soybean (steers) 49.8 53.8 28. 55.3 42.9 61.2 48.9 

1 . Soybean (goats) 59. 59.3 56.7 75.7 54.8 52. 71.9 

1 . Com and soybean 69. 71. .. 65. 64.8 74.9 82.1 

1 . Millet and soybean 58.8 59.9 .. 58.4 69.4 59.2 72.2 

1 . Com, horse beans, and 

sunflower heads 65.6 67.8 41.1 62.7 60.1 72.4 76.7 

1 . Com, horse beans, and 

sunflower plants. .. . 65.5 69.3 25.6 58. 65.3 73.7 74.1 

Dried Fodders f 

Meadow Grasses / 
1 . Black grass {Juncus 

bulbosus) 59.5 . . . . 63. 60.5 57. 41.5 

1 , Black grass {Juncus 

Gerardii) 53.4 52.1 69. 54.3 57.4 49. 45.7 

2 . Blue joint 54.3 55.8 29.4 63.4 54.5 55.9 44.7 

1 . Branch grass {Spar- 
Una stricta glabra) . . . 56. . . . . 62.5 52. 54. 32. 

1 . Branch grass {Distichlis 

spicata) 49.7 48.9 58.1 51.7 56.4 45.7 36.6 

1 . Chess or cheat 45. 47.3 23. 42. 46. 49. 32. 

2. Crab grass 53.6 55. 37.6 .. 59.1 54.5 46.8 

1 . Fox grass {Spartina 

patens) 54.8 54.5 58.2 59.3 57.4 53.1 36.4 

1 . Fox grass {Spartina 

juncea, etc.) 53 57. 51. 52. 24. 

1 . Flat sage 56.1 57.3 62. 51.8 60.4 55.1 36.1 

1 . Hungarian grass 65. 66.3 47.4 60. 67.6 67.1 63.9 

2 . Johnson grass 56.5 58.3 30.5 41.4 65.7 56.9 38.4 

1 . Bamyard millet 57.4 56.8 63.1 63.7 61.6 51.6 46.3 

1 . Cat-tail millet 62.3 61.6 68.4 62.6 66.5 59.1 46.1 

2 . Orchard grass 56.6 57.8 . . 59.5 60.4 55.4 53.8 

2 . Red-top 59.7 61.2 29. 61.3 61.3 61.9 50.5 

1 . Red-top and sedge 46. 48.5 10 1 37.2 55.7 45.6 49. 

17 . Timothy 56.5 57.9 32.8 46.9 52.5 62.3 52.2 



44^ 


1 


APPENDIX 


















"^IflTOO+lO'^ n/N/4flK^»i4:iT\ + e* . 














-/igesti" 


JXX V.»-f^XX. 


Nitrogen- 


No. 


ex- Kind and condi- 


Dry Organic 




Pro- 




free ex- 




perim'ts tion of food 


matter matter 


Ash 


tein 


Fiber 


tract 


Fat 






% 


% 


% 


% 


% 


% 


% 


Meadow Grasses — continued 
















3 


Timothy, before or in 


















bloom 


60.7 


61.5 


44.2 


56.8 


58.8 


64.3 


58.4 


4 


Timothy, past bloom . . 


53.4 


54.5 


30.3 


45.1 


47.1 


60.4 


51.9 


1 


Timothy rowen 


62.2 


64.4 


56.4 


68. 


66.5 


63.4 


49.5 


2 


Wild-oat grass 


64. 


65.2 


34.7 


58.3 


67.9 


65.5 


50.5 


2 


Witch grass 


61.2 


62.3 


40.9 


58.6 


62.8 


65.6 


57.2 


1 


Black grass and red- 


















top (cove mixture)... 


54.6 


54.3 


57.5 


47.9 


59.7 


53.2 


40.3 


5 


Mixed grasses 

Meadow hay — 


57.1 


58.8 


• • 


58.5 


59.7 


58.7 


48.5 




Best (G) 


. . 


67. 


. , 


65. 


63. 


68. 


57. 




Medium (G) 


, , 


61. 


, . 


57. 


60. 


64. 


53. 




Poor (G) 




56. 




50. 


56. 


59. 


49. 


2 


Pasture grass 


72.6 


73.2 


61*8 


73.4 


76.1 


74.2 


67.3 


1 


Swale hay 


39. 






34. 


33. 


46. 


44. 


1 


High-grown salt hay. . . 


53. 


, , 


, , 


63. 


50. 


53. 


47. 


1 


Salt-hay mixture 


56.4 


54.9 


69.8 


42.6 


60.7 


54.7 


29.7 


2 


Rowen hay 


64.4 


65.8 


46.6 


69.1 


66.6 


66.2 


47.4 




Cereal Plants 
















1 


Barley hay 


61.2 


62.3 


44.8 


65.2 


61.7 


63 3 


40. 


17 


Dent com fodder 


64.3 


66.1 


30.7 


50.4 


62.2 


68. 


73.6 


7 


Flint com fodder 


68.6 


71.7 


42.6 


60. 


74.9 


70.3 


71.4 


13 


Dent and flint com 


















fodders (immature). . 


63.9 


65.7 


37.2 


51.7 


66. 


66.2 


72.2 


10 


Dent and flint corn 


















fodders (mature) .... 


68.2 


70.7 


30.6 


56.1 


65.8 


72.2 


73.9 


3 


Sweet com fodder 


67.2 


69.8 


35.6 


64.1 


73.8 


68.2 


73.6 


5 


Com stover 


57.2 


59.1 


32.6 


35.9 


64.2 


57.9 


70.4 


3 


New com product 


58.1 


59.2 


38.7 


46.7 


57. 


60.5 


78.2 


2 


Topped com fodder. . . . 


57.4 


62.3 


3.8 


38.7 


71. 


57.9 


67.4 


1 


Com blades and husks. 


63.8 


67.1 


22.6 


47.7 


72.9 


66.4 


58.1 


2 


Corn leaves (pulled 


















fodder) 


59.8 


63.6 


26.8 


48.4 


67.5 


63. 


59.9 


1 


Com husks 


72. 


74.2 


16. 


29.5 


79.5 


75. 


32.5 


1 


. Corn butts 


66.5 
49.3 


69.4 
50.1 


11.5 
34.6 


21. 
54.2 


73.5 
43.5 


69. 
52. 


79.5 


1 


. Oat hay 


61.9 


1 


Oat straw 


50.3 


52. 
55. 




49.' 


57.6 
43. 


53.2 
67. 


38.3 




Bean straw 


57. 




Wheat straw (G) 




46. 




23. 


55. 


39. 


36. 




Rye straw (G) 




48. 




25. 


63. 


39. 


29. 




Barley straw (G) 




53. 




25. 


55. 


54. 


42. 




Rice straw (G) 




47. 




45. 


57 


32. 


47. 


1 


. Sorghum fodder (pulled) 


63.1 


64.8 


29.5 


60.8 


70.4 


64.5 


46.7 


1 


. Sorghum bagasse 


60.6 


62.2 


13.4 


13.7 


63.8 


64.8 


46.4 



COEFFICIENTS OF DIGESTION 



445 



Digestion coefficients ■ 



No. ex- 
perim'ts 



Kind and condi- 
tion of food 



Dry Organic 
niatter matter 



% % 

Clovers 

2 . Alsike clover 62.3 63.2 

4 . Crimson clover 58.1 59.1 

6. Red clover 57.4 59.7 

2 . Red-clover rowen 58. 59.1 

1 . White clover 66. 66.6 



Legumes Other Than Clovers 

S.Alfalfa 58.9 

1 . Cowpea vine 59.2 

1 . Peanut vine 59.9 

1 . Soybean 62.4 

1 . Hairy vetch 69.4 

Bean straw (G) 

Pea straw, good (G) 

Miscellaneous and Mixed 

1 . Buttercup hay 56.1 

1 . Whiteweed hay 57.8 

2 . Clover and timothy. ... 54.6 

1 . Vetch and oats 58.1 

Grains and Seeds 

Barley (G) 

Oats (G) 

5 . Com meal 89.4 

2 . Corn-and-cob meal. . . . 78.7 

1 . Rye mieal 87.3 

1. Pea meal 86.8 

Field beans 

1 . Soybean meal 81.9 

1 . Cottonseed, raw 66.1 

1 . Cottonseed, roasted.. . . 55.9 

Linseed 

Acorns 



Ash 

% 

52.2 
51.9 
29.1 
45.8 
58.5 



39.5 
49.5 
20.4 

42.2 



60.7 

60. 

63.1 

63.9 

71.8 

55. 

59. 



56.6 48.1 
58.3 52. 
53.2 . . 

58.7 . . 



86. 

71. 

89.6 

79.8 

88.7 

87.9 

89. 

84. 

65.8 

56.8 

77. 

88. 



43.7 



43.3 



Pro- 
tein 

% 

66.1 

68.7 
58. 
64.8 
73.2 



72. 

64.8 

63.3 

71.1 

82.3 

49. 

60. 



70. 

78. 

67.9 

55.6 

84.4 

83.2 

88. 

91.1 

67.8 

46.9 

91. 

83. 



Fiber 

% 

53.5 

46.7 
54.2 
47.4 
60.6 



46. 

42. 

51.9 

60.8 

61.1 

43. 

52. 



Nitrogen- 
free ex 
tract 

% 



70.7 
64.6 
64.4 
62.8 
69.5 



69.2 

70.6 

69.5 

68.8 

72.9 

67. 

64. 



26. 

45.7 

25.7 

72. 

71.2 

75.5 

65.9 

60. 

62. 



92. 

77. 

94.6 

87.6 

91.9 

93.6 

92. 

76.3 

49.6 

51.4 

55. 

91. 



Fat 

% 



50.2 
43.4 
55.2 
59.8 
50.6 



51. 

51.8 

65.9 

29.2 

70.3 

57. 

46. 



56.3 41.1 66.9 69.7 

58.4 45.5 66.7 62. 
42.3 49.6 57.5 54. 
59.7 66. 54.2 18.6 



89. 

83. 

92.1 

84.1 

64.2 

54.5 

81. 

85.7 

87.1 

71.7 

86. 

87. 



By-Products 
Cereals 
1 . Atlas meal 

1 . Cerealine feed 

2 . Com cobs 

1 . Dried brewers' grains. 

5 . Gluten feed 

4 . Gluten meal 

1 . H. O. dairy feed 



79.6 
90.4 
51.4 
61.6 
86.3 
89.7 
65.3 



83.4 
92.7 

65.4 
87.3 
90.4 
68. 



72.8 


105.7 


84.5 


91.2 


76.6 


82.2 


95.3 


80.6 


19.3 


57.5 


48.3 


, ^ 


79.3 


52.6 


57.8 


91.1 


85.6 


78. 


89.2 


84.4 


88.2 




89.8 


94.4 


77.8 


40.8 


69.9 


85.5 



446 APPENDIX 

, Digestion coefl5cients ^ 

Nitrogen- 
No. ex- Kind and condi- Dry Organic Pro- free ex- 
perim'ts tion of food matter matter Ash tein Fiber tract Fat 

% % % % % % % 
Cereals — continued 

1 . H. O. horse feed 70.1 72.6 .. 74.4 35.2 78.7 84. 

1. Maize feed 87.1 87.1 .. 85.5 82.5 87.9 91.5 

1 . Maltsprouts 67.1 67.2 . . 80.2 32.9 68.1 104.6 

1 . Quaker oat feed 62. 65.3 .. 81.1 42.6 67.4 89. 

1 . Victor com - and - oat 

feed 74.7 77.4 .. 70.8 48.3 83. 86.8 

7. Wheat bran 62.3 65.7 .. 77.8 28.6 69.4 68. 

1 . Wheat bran and shorts. 60.2 60.7 7.5 75.8 18.3 64.3 45. 

3 . Wheat middlings 75. 78.5 .. 79.8 33.1 81.3 86.3 

Oil-hearing Seeds 

3 . Cottonseed hulls 39.8 40.5 23.2 . . 40. 41.1 85.7 

5 . Cottonseed meal 73.7 76.1 23.7 88.4 55.5 60.6 93.3 

1 . Linseed meal, old pro- 

cess 78.7 81.2 . . 88.8 57. 77.6 88.6 

2 . Linseed meal, new pro- 

cess 79.2 81.8 .. 85.2 80.4 86.1 96.6 

MiscellaneoiLS 

1. Peanut feed 32.1 32.8 .. 70.6 11.7 49.1 89.7 

1 . Rice meal 73.8 81.6 . . 61.9 . . 92.3 91.1 

Roots 

1 . Mangolds 78.5 84.8 16.4 74.7 42.8 91.3 

1 . Potatoes, raw 75.7 77. . . 44.7 . . 90.4 13. 

1 . Potatoes, boiled 80.1 81.2 .. 43.4 .. 92.1 

1 . Rutabagas 87.2 91.1 31.2 80.3 74.2 94.7 84.2 

1 . Sugar-beets 94.5 98.7 31.9 91.3 100.7 99.9 49.9 

1 . Turnips 92.8 96.1 58.6 89.7 103. 96.5 87.5 

Animal Products 

Cow's milk (G) 98. . 94. . . 98. 100. 

Meat meal (G) 93. ..96 99. 

Dried blood (G) 63. 62. . . 100. 100. 

Dried fish, ground (G) 90 76. 



Digestion by Horses 

Dried Fodders 

2 . Timothy hay in full 

bloom, well cured. .. . 43.5 44.1 34. 
2 . New com product 49.9 51.7 21.7 



21.2 

67.5 



42.6 
54.6 



47.3 
46.9 



47.3 

59.8 



COEFFICIENTS OF DIGESTION 



447 



Naex- 

perim'ts 



Kind and condi- 
tion of food 



Dried Fodders — continued 
Meadow hay — 

Best (G) 

Medivun (G) 

Poor (G) 

Red-clover hay (G). . . . 

Alfalfa hay (G) 

Wheat straw (G) 



Dry Organic 
matter matter 

% % 



Digestion coeflScients 

Nitrogen- 
Pro- free ex- 
Ash tein Fiber tract Fat 

% % % % % 



58. 
50. 
46. 
51. 
58. 
21. 



63. 
57. 
55. 
56. 
73. 
28. 



48. 
39. 
38. 
37. 
40. 
18. 



65. 

58. 
52. 
63. 
70. 

28. 



22. 
18. 
24. 
29. 
14. 
66. 



Roots 

Potatoes (G). 
Carrots (G) . . 



93. 

87. 



88. 
99. 



99. 
94. 



Grains 

Oats (G) 

Barley (G) 

Com (G) 

Field beans (G) 

Peas (G) 

2 . Dent com, unground... 74.4 
2 . Com meal, same ma- 
terial, ground 88.4 

2 . White oats, first qual- 
ity, unground • 72.4 

2 . Oats, same material, 



69. 

87. 
89. 
87. 
80. 
75.3 



26.3 



79. 

80. 
76. 
86. 
83. 

57.8 



29. 75. 



40. 
65. 

8. 
(?) 



87. 
92. 
94. 
89. 

88.2 



71. 
42. 
61. 
13. 

7. 
47.7 



75.6 (?) 95.7 73.1 



74.1 33.1 86.1 31.1 79.4 82.4 



ground 75.7 77.7 29.2 82.4 14.4 86.1 79.9 



Digestion by Swine 
Grains and Seeds 

. Barley, whole kemel . . 80.1 80.3 5.4 81.4 

. Flint com, unground . 89.7 91.3 . . 89.9 

. Com meal, same mate- 
rial, finely ground . . 89.5 91.2 .. 86.1 

. Com -and -cob meal, 

whole ear ground . . 75.6 76.7 . . 75.7 

, Wheat, unground 72. . . 44. . 70. 

. Wheat, cracked 82. . . 50. 80. 

.Peas, ground 89.8 91.5 40.3 88.6 

By-products 

.Wheat bran 65.8 .. .. 75.1 

Rye bran (G) 67. . . 66. 

. Wheat shorts 76.5 . . 5.4 73.5 

. Linseed meal 77.5 . . 10. 86. 



/ 



48.7 86.6 57. 

48.7 93.9 77.6 

29.4 94.2 81.7 

28.5 83.6 82. 
30. 74. 60. 
60. 83. 70. 
77.9 95.1 50. 



33. 65.5 71.8 

9. 74. 58. 

36.5 86.8 

12. 85. 80. 



448 APPENDIX 

f Digestion coefficients % 

Nitrogen- 
No. ex- Kind and condi- Dry Organic Pro- free ex- 
perim'ts tion of food matter matter Ash tein Fiber tract Fat 

% % % % % % % 

Roots 

2 . Potatoes, raw 97. . . 44.6 84.5 . . 98.1 

2 . Potatoes, cooked 95. . . 40. 82. . . 97.6 

Animal Products 

Meat meal (G) 92, . . 97 86. 

Dried blood (G) 72. . . 72. . 92. 

Sour milk (G) 95. . . 96. . . 98. 95. 

3. COMPUTATION OF ENERGY-PRODUCTION VALUES 
(TO THE 100 POUNDS) 

The following remarks and tables are by Armsby and 
Putney (Pennsylvania Experiment Station, Bulletin No. 
142), who write: '*It is obviously impracticable to apply 
the laborious methods of respiration and calorimeter 
experiments to all the great variety of feeding-stuffs now 
in use. It does appear possible, however, to select a few 
typical representatives of the different classes and to apply 
the results obtained upon them to other similar materials, 
much as is even yet done to a considerable extent with the 
results of digestion experiments. The somewhat compli- 
cated method used by Kellner for this purpose has 
already been described in Bulletin No. 71 of this Station 
as well as in Kellner's smaller textbook, of which an 
English translation entitled *The Scientific Feeding of 
Farm Animals' has lately been published. (Kellner 
expresses the results in terms of so-called *starch values,' 
which are really energy values and can equally well be 
expressed in Therms.) A simpler method, however, can 
be used. Extensive tables are available which show with 
more or less accuracy for a large number of feeding-stuffs 
the digestible nutrients, the sum of which, of course, makes 
up the total digestible organic matter." 



ENERGY-PRODUCTION VALUES 449 

As an illustration of the method of computation we 
may take average timothy hay, containing the following 
amounts of digestible matter: 

In 100 Pounds of Timothy Hay 

Pounds 

Dry matter 88.4 

Digestible 

Protein 3. 

Carbohydrates 42.8 

Fat 1.2 

Total digestible organic matter 47. 

According to previous figures, each pound of digestible 
organic matter in roughage contains approximately 1.588 
Therms of metabolizable energy, while Table 1 shows 
that each pound of dry matter of timothy hay causes a 
heat expenditure of 0.3547 Therms. The net energy value, 
therefore, of the 88.4 pounds of dry matter contained in 
100 pounds of the hay would be : 

Metabolizable energy . . 1.588 Therms x 47.0=74.64 Therms 
Heat expenditm-e 0.3547 Therms x 88.4=31.36 Therms 

Net energy value 43.28 Therms 

Continuing, Armsby and Putney discuss the net energy 
values of American feeding-stuffs as follows: 

"Henry and Morrison ('Feeds and Feeding,' 15th 
edition, pages 633-66) have recently published a very 
valuable compilation of American analyses of feeding- 
stuffs and of the results of American digestion experi- 
ments, and on this basis have calculated the content of 
digestible nutrients (for ruminants) in a great variety of 
feeding-stuffs. 

"With the permission of these authors, we have under- 
taken to compute from their tables the net energy values 
of the more important feeding-stuffs in the manner illus- 
cc 



450 APPENDIX 

trated in the last paragraph of the foregoing paper and 
with the results contained in the following table, which 
includes also the digestible (true) protein and the non- 
protein. In regard to this table it is to be remarked: 

*^ First, both the digestion coeflBcients used by Henry 
and Morrison and the data for the expenditure of energy 
due to feed consumption are derived exclusively from 
experiments on ruminants (in the latter case, on cattle). 
Consequently, the net energy values here computed are ap- 
plicable to ruminants only and not to horses nor to swine. 

"Secondy the table shows primarily the net energy 
values for maintenance or fattening. There seems good 
reasons for believing, however, that they may be taken 
without serious error to represent also the net energy 
values for growth and at least the relative values for 
milk production. 

*' Third, in comparing the figures for the various feed- 
ing-stuffs, account should be taken of the differences in 
moisture-content. Many of Henry and Morrison's 
averages for dry feeds show a remarkably low moisture- 
content, tending to raise the suspicion that some of the 
analyses averaged were made on partially dried samples, 
although the authors state that every precaution was 
taken to exclude such cases from the compilation. It is 
evident at least that more study of the actual percentage 
of moisture in feeding-stuffs as they are used in practice 
is much to be desired. 

*' Fourth, Henry and Morrison's tables include only the 
crude protein (N X 6.25). The amount of non-protein 
has been estimated from the crude protein by the writers 
on the basis of Kellner's averages." 

In accordance with the method and data mentioned 
the following table was calculated : 



ENERGY-PRODUCTION VALUES 



451 



Average Dry Matter, Digestible Crude Protein, Digestible 

True Protein, and Net Energy Values to the 100 Pounds 
FOR Ruminants: 

' Digestible > Net 

Dry Crude True energy 

matter protein protein value 

Pounds Pounds Pounds Therms 

Dried Roughage 

Hay and Fodder from Cereals 

Brome grass, smooth 91.5 5. 3.5 40.83 

Com fodder (ears included, medium dry) 81.7 3. 2.3 43.94 

Corn stover (ears removed, medium dry) 81. 2.1 1.6 31.62 

Millet, Hungarian 85.7 5. 3.9 46.96 

Mixed timothy and clover 87.8 5.3 3.2 41.07 

Oat Hay 88. 4.5 3.9 32.25 

Orchard grass 88.4 4.7 3.3 44.93 

Red top 90.2 4.6 3.9 51.22 

Timothy, all analyses 88.4 3. 2.2 43.02 

Timothy, before bloom 92.8 4.7 2.9 43.52 

Timothy, early to full bloom 87.2 3.6 2.5 47.4 

Timothy, late bloom to early seed 85.1 2.4 1.8 37.54 

Timothy, nearly ripe 87.5 2.2 1.8 38.59 

Hay and Fodder from Legumes 

Alfalfa, all analyses 91.4 10.6 7.1 34.23 

Alfalfa, before bloom 93.8 15.4 10.3 36.23 

Alfalfa, in bloom 92.5 10.5 6.7 32.33 

Alfalfa, in seed 89.6 8.5 6.2 32.23 

Clover, alsike 87.7 7.9 5.3 34.42 

Clover, crimson 89.4 9.7 6.9 36.21 

Clover, red, all analyses 87.1 7.6 4.9 38.68 

Clover, red, before bloom 89.6 11.6 5.4 42.17 

Clover, red, in bloom 86.1 8.1 5.3 39.12 

Clover, red, after bloom 77.9 6.8 4.5 34.51 

Clover, sweet, white 91.4 10.9 6.7 38.98 

Cowpeas, all analyses 90.3 13.1 9.2 37.59 

Cowpeas, before bloom 92.2 17.8 12.8 33.54 

Cowpeas, in bloom to early pod 89.4 12.6 9.5 39.11 

Soybeans 91.4 11.7 8.8 44.03 

Straws 

Barley 85.8 .9 .6 36.61 

Buckwheat 90.1 4.2 3.2 4.55 

Oat 88.5 1. .8 34.81 

Rye 92.9 .7 .5 17.59 

Wheat 91.6 .7 .3 7.22 




452 APPENDIX 

, Digestible , Net 

Dry Crude True energy 

matter protein protein value 

Pounds Pounds Pounds Therms 
Fresh Gbeen Roughage 

Green Cereals, Etc. 

Barley fodder 23.2 2.3 2. 14.08 

Blue-grass, Kentucky, before heading... 23.8 3.7 2.8 14.82 

Blue-grass, Kentucky, headed out 36.4 2.8 2.2 17.77 

Blue-grass, Kentucky, after bloom 43.6 1.9 1.6 21.01 

Buckwheat, Japanese 36.6 2.2 1.5 17.78 

Cabbage 8.9 1.9 1.3 8.87 

Cabbage, waste outer leaves 14.1 1.7 1.1 7.05 

Com fodder, dent, all analyses 23.1 1. .8 14.6 

Corn fodder, dent, in tassel 14.9 1.1 .8 9.52 

Corn fodder, dent, in milk 19.9 1. .8 13.64 

Corn fodder, dent, dough to glazing. .. . 25.1 1.3 1. 17.35 

Corn fodder, dent, kernels glazed 26.2 1.1 .8 16.74 

Corn fodder, dent, kernels ripe 34.8 1.5 1.1 22.48 

Corn fodder, flint, all analyses 20.7 1. .8 13.53 

Corn fodder, flint, in tassel 10.6 .9 .7 6.89 

Corn fodder, flint, in milk 15. .9 .7 10.39 

Corn fodder, flint, kernels glazed 21. 1. .8 13.49 

Corn fodder, flint, kernels ripe 27.9 1.2 .9 17.84 

Corn fodder, sweet, before milk stage. . . 10. .8 .6 7.82 

Corn fodder, sweet, roasting-ears or later 20.3 1.2 .9 13.38 

Corn fodder, sweet, ears removed 21.5 1. .8 14.26 

Millet, Hungarian 27.6 1.9 1.1 17.24 

Oat fodder 26.1 2.3 2. 14.06 

Orchard grass 29.2 1.7 1.1 15.81 

Rape 16.7 2.6 1.7 13.07 

Rye fodder 21.3 2.1 1.4 15.99 

Sweet sorghum fodder 24.9 .7 .4 15.37 

Timothy, before bloom 24.2 1.8 1.1 18.36 

Timothy, in bloom 32.1 1.3 .8 18.89 

Timothy, in seed 46.4 1.5 1. 26.36 

Wheat fodder 27.4 2.8 1.9 18.75 

Green Legumes 

Alfalfa, before bloom 19.9 3.5 1.9 9.2 

Alfalfa, in bloom 25.9 3.3 1.8 11.5 

Alfalfa, after bloom 29.8 2.1 1.3 11.1 

Clover, alsike 24.3 2.7 1.5 14.56 

Clover, crimson 17.4 2.3 1.6 10.83 

Clover, red, all analyses 26.2 2.7 1.7 15.87 

Clover, red, in bloom 27.5 2.7 1.8 16.74 

Clover, red, rowen 34.4 3.3 2.2 17.3 

Cowpeas 16.3 2.3 1.7 10.42 

Peas, Canada field 16.6 2.9 2.1 9.78 

Soybeans, all analyses 23.6 3.2 2.4 12.53 

Soybeans, in bloom 20.8 3. 2.3 10.44 



ENERGY-PRODUCTION VALUES 



453 



Dry 
matter 

Green Legumes — continued roun 

Soybeans, in seed , 24.2 

Vetch, hairy 18.1 

Silage 

Com, well-matured, recent analyses. . . . 26.3 

Corn, immature 21. 

Corn, from frosted ears 25.3 

Com, from field-cured stover 19.6 

Clover 27.8 

Cowpeas 22. 

Soybeans 27.1 

Sugar-beet pulp 10* 

Roots, Tubers and Fruits 

Apple 18.2 

Beet, common 13. 

Beet, sugar- 16.4 

Carrot 11.7 

Mangels 9.4 

Potatoes 21.2 

Pumpkin, field 8.3 

Rutabaga 10.9 

Turnip 9.5 

Grains 
Cereal Grains 

Barley 90.7 

Buckwheat 87.9 

Corn, dent 89.5 

Com, flint 87.8 

Com-and-cob meal 89.6 

Corn meal 88.7 

Oats 90.8 

Oatmeal 92.1 

Rye 90.6 

Wheat, all analyses 89.8 

Wheat, winter 89.1 

Wheat, spring 89.9 

Leguminous Seeds 

Bean, navy 86.6 

Cowpea 88.4 

Pea, field 90.8 

Pea meal 89.1 

Peanut with hull 93.5 

Peanut kernel 94. 

Soybean 90.1 



, Digestibl 

Crude 
protein 

Pounds 



-. Net 
True energy 
protein value 

Pounds Therms 



3.1 
3.5 

1.1 

1, 

1.2 

.5 
1.3 
1.8 
2.6 

.8 



.4 
.9 

1.2 
.8 
.8 

1.1 

1.1 

1. 

1, 



9. 

8.1 
7.5 
7.7 
6.1 
6.9 
9.7 
12.8 
9.9 
9.2 
8.7 
9.2 



18.8 

19.4 

19. 

19.8 

19.4 

24.1 

30.7 



2.5 
2.4 



.6 
.4 
.6 
.3 
.8 
1.1 
1.5 
.5 



.1 
.1 
.4 
.6 
.1 
.1 
.6 
.3 
.4 



8.3 
7.2 
7. 
7.2 
5.7 
6.4 
8.7 
11.5 
9. 
8.1 
7.7 
8.1 



16.4 
16.9 
16.6 
17.2 
16.9 
22.2 
27.3 



12.7 
11.95 

15.9 

11.96 

14.27 

8.98 

7.26 

11.05 

11.59 

9.32 



15.92 
7.84 

11.2 
9.21 
5.68 

18.27 
6.05 
8.46 
6.16 



89.94 

59.73 

89.16 

87.5 

75.8 

88.75 

67.56 

86.2 

93.71 

91.82 

91.66 

91.41 



73.29 
79.46 
78.72 
77.62 
83.15 
109.04 
81.29 



454 



APPENDIX 



Dry 

matter 

Pounds 
Oil Seeds 

Cotton seed 90.6 

Flax seed 90.8 

Sunflower seed 95.5 

Sunflower seed with hulls 93.1 

Dairy Products 

Buttermilk 9.4 

Cow's milk 13.6 

Skim-milk — centrifugal 9.9 

Skim-milk — gravity 9.6 

Skim-milk— dried 91.7 

Whey 6.6 

By-Products 

Fermentation Industries 

Brewers' grains, dried 92.5 

Brewers' grains, dried, below 25 per 

cent protein 91.8 

Brewers' grains, wet 24.1 

Distillers' grains, dried, from com 93.4 

Distillers' grains, dried, from rye 92.8 

Distillers' grains, wet 22.6 

Malt 94.2 

Maltsprouts 92.4 

Milling 

Buckwheat bran 88.8 

Buckwheat hulls 89.7 

Buckwheat middlings 88. 

Hominy feed 89.9 

Rye bran 88.6 

Wheat bran 89.9 

Wheat middlings, flour 89.3 

Wheat middlings, standard 89.6 

Oil Extraction 

Coconut meal, low in fat 90.4 

Coconut meal, high in fat 92.3 

Cottonseed hulls 90.3 

Cottonseed meal, choice 92.5 

Cottonseed meal, prime 92.2 

Germ oil meal, corn 91.1 

Linseed meal, new process 90.4 

Linseed meal, old process 90.9 

Palmnut cake 89.6 



I Digestible > Net 

Crude True 
protein protein 

Pounds Pounds Therms 



energy 
value 



13.3 
20.6 
23.3 
13.5 



3.4 
3.3 

3.6 

3.1 

34.4 

.8 



11.9 
19.2 
20.2 
11.7 



3.4 
3.3 
3.6 
3.1 
34.4 
.8 



78.33 
83.17 
95.77 
92,49 



13.32 
29.01 
14.31 
15.43 
103.91 
10.39 



21.5 20.2 53.38 



18.7 


17.5 


50.93 


4.6 


4.4 


14.53 


22.4 


18.3 


85.08 


13.6 


11.1 


56.01 


3.3 


2.8 


22.05 


15.8 


11.8 


87.82 


20.3 


12.5 


72.72 


10.5 


9.1 


30.59 


.4 


? 


-7.69 


24.6 


20.8 


72.19 


7. 


6.5 


81.31 


12.2 


10.5 


79.35 


12.5 


10.8 


53. 


15.7 


14. 


75.02 


13.4 


12. 


59.1 


18.8 


18.3 


83.49 


18.4 


18. 


100.31 


.3 


? 


9.92 


37. 


35.4 


93.46 


33.4 


32. 


90. 


16.5 


14.3 


83.88 


31.7 


30.9 


85.12 


30.2 


28.5 


88.91 


12.4 


12. 


94.18 



MILK PRODUCTION 



455 



Dry 

matter 

Pounds 
Oil Extraction — continued 

Peanut cake from hxilled nuts 89.3 

Peanut cake, hulls included 94.4 

Soybean meal, fat extracted 88.2 

Sunflower seed cake 90. 

Starch Manufacture 

Gluten feed 91-3 

Gluten meal 90.9 

Starch feed, dry 90.7 

Starch feed, wet 33.4 

Sugar Manufacture 

Molasses, beet 74.7 

Molasses, cane or black strap 74.2 

Molasses beet pulp 92.4 

Sugar-beet pulp, dried 91.8 

Sugar-beet pulp, ensiled 10. 

Sugar-beet piilp, wet 9.3 

Packing-House 

Dried blood 90.3 

Tankage 

Over 60 per cent protein . . . 92.6 

55-60 per cent protein 92.5 

45-55 per cent protein 92.5 

Below 45 per cent protein 93.5 



Digestible- 


N Net 


Crude 


True 


energy 


protein 


protein 


value 


Pounds 


Pounds Therms 


42.8 


41.4 


93.55 


20.2 


19.5 


42.57 


38.1 


37.3 


99.65 


32. 


29.1 


88.87 


21.6 


20.1 


80.72 


30.2 


28.1 


84.15 


11.2 


9.2 


77.46 


4.1 


3.7 


30.45 
I 


1.1 


, ^ 


57.1 


1. 


. . 


55.38 


5.9 


3.5 


76.28 


4.6 


.7 


75.87 


.8 


.5 


9.32 


.6 


.6 


8.99 



69.1 68.6 68.12 



58.7 


55.6 


93.04 


54. 


51.1 


83.58 


48.1 


45.5 


72.96 


37.6 


35.6 


54.16 



STANDARDS FOR MILK PRODUCTION AS DEVELOPED 
BY HAECKER, SAVAGE, AND ECKLES 

Protein and Total Nutrients for One Pound of Milk 



'er cent 
fat in 


, Haecker v 

Total 
Protein nutrients 


, Savage 

Total 
Protein nutrients 


, Eckles , 

Total 
Protein nutrients 


milk* 


Pounds 


Pounds 


Pounds 


Pounds 


Pounds Pounds 




.07 


.78 


.07 


.7925 




2.5 


.039 


.219 


.0527 


.2574 




2.6 


.0396 


.224 


.0535 


.2629 




2.7 


.0402 


.229 


.0543 


.2685 




2.8 


.0408 


.233 


.0551 


.2743 




2.9 


.0414 


.239 


.0559 


.2812 




3. 


.042 


.244 


.0567 


.287 




3.1 


.0426 


.249 


.0575 


.2928 





*For maintenance, per 100 pounds 



456 



APPENDIX 



Per cent 




,. Savage , 


f Eckles » 


fat in 




Total 




Total 


Total 


milk* 


Protein 


nutrients 


Protein 


nutrients 


Protein nutrients 




Pounds 


Pounds 


Pounds 


Poxinds 


Pounds Poxinda 


3.2 


.0432 


.254 


.0583 


.2987 




3.3 


.0438 


.26 


.0591 


.3055 




3.4 


.0444 


.265 


.0599 


.3115 


.0469 .285 


3.5 


.045 


.271 


.0608 


.3185 




3.6 


0456 


.276 


.0616 


.3243 




3.7 


.0462 


.282 


.0624 


.3312 




3.8 


.0468 


.287 


.0632 


.3369 


.051 .283 


3.9 


.0474 


.292 


.064 


.3428 


.056 .298 


4. 


.048 


.297 


.0648 


.3497 




4.1 


.0486 


.302 


.0656 


.3555 




4.2 


.0492 


307 


.0664 


.3612 




4.3 


.0498 


.312 


.0672 


.3671 




4.4 


.0504 


.317 


.068 


.3729 




4.5 


.051 


.322 


.0689 


.3787 




4.6 


.0516 


.327 


.0697 


.3842 




4.7 


.0522 


.331 


.0705 


.389 




4.8 


.0528 


.335 


.0713 


.3945 




4.9 


.0534 


.339 


.0721 


.3992 




5. 


.054 


.344 


.0729 


.4048 


/ 


6.1 


.0546 


.349 


.0737 


.4105 




6.2 


.0552 


.353 


.0745 


.415 




5.3 


.0558 


.357 


.0753 


.4209 


.048 .332 


5.4 


.0564 


.361 


.0761 


.4253 




5.5 


.057 


.366 


.077 


.4311 


.0587 .396 


5.6 


.0576 


.37 


.0778 


.4355 




5.7 


.0582 


.375 


.0786 


.4413 




5.8 


.0588 


.38 


.0794 


.4469 




5.9 


.0594 


.384 


.0802 


.4517 




6. 


.06 


.388 


.081 


.4572 




6.1 


.0606 


.392 


.0818 


.4619 


.072 .605 


6.2 


.0612 


.397 


.0826 


.4676 




6.3 


.0618 


.401 


.0834 


.4721 




6.4 


.0624 


.407 


.0842 


.4791 




6.5 


.063 


.41 


.0851 


.4835 




6.6 


.0636 


.415 


.0859 


.4882 




6.7 


.0642 


.419 


.0867 


.4926 




6.8 » 


.0648 


.423 


.0875 


.4984 




6.9 


.0654 


.428 


.0883 


.504 




7. 


.066 


.431 


.0891 


.5075 





♦For maintenance, per 100 pounds. 



FEEDING STANDARDS 457 

6. FEEDING STANDARDS 

The feeding standards for the various classes of farm 
animals are taken from Mentzel & Lengerke's Landw. 
Kalender for 1899. They are intended to apply to ani- 
mals of average size fed under normal conditions. They 
are not to be regarded as feeding recipes, but are to be 
varied according to circumstances. Small animals should 
receive proportionately more food than large ones; milch 
cows in proportion to the quantity and richness of the 
milk; growing and fattening animals according to the 
rapidity of increase desired; work animals according to 
the severity of labor, and individual animals according 
to their peculiar needs. 

The quantity of "dry substance" will vary according 
to the digestibility of the ration, with no harm. It is 
important to maintain the necessary quantity of diges- 
tible dry substance. This should be somewhat more if 
the ration has a larger proportion of coarse materials 
than when it is mostly grain. The nutritive ratio may 
widely vary according to the availability and price of 
feeding-stuffs. The method of calculating a standard 
ration is explained in Chapter XIX. 



Per 1,000 Lbs. Live Weight, Daily 
Dry ^Digestible organic substances— n Nutri- 

sub- Pro- Carbo- tive 

Kind of animal stance tein hydrates Fat Total ratio 1: 

Lbs. Lbs. Lbs. Lbs. Lbs. 

1 . Oxen — 

At rest 18 .7 8. .1 8.8 11.8 

Light work 22 1.4 10. .3 11.7 7.7 

Moderate work 25 2. 11.5 .5 14. 6.5 

Severe work 28 2.8 13. .8 16.6 5.3 

2 . Fattening bovines — 

First period 30 2.5 15. .5 18. 6.5 

Second period 30 3. 14.5 .7 18.2 5.4 

Third period 26 2.7 15. 7 18.4 6.2 



458 APPENDIX 

Per 1,000 Lbs. Live Weight, Daily 

Dry /—Digestible organic substances-^ Nutri- 

sub- Pro- Carbo- tive 

Kind of animal stance tein hydrates Fat Total ratio 1: 

Lbs. Lbs. Lbs. Lbs. Lbs. 

3 . Milch cows — 

Daily milk yield 11 

pounds 25 1.6 10. .3 11.9 6.7 

Daily milk yield 16J^ 

pounds 27 2. 11. .4 13.4 6. 

Daily milk yield 22 

pounds 29 2.5 13. .5 16. 5.7 

DaHy milk yield 27V^ 

pounds 32 3.3 13. .8 17.1 4.5 

4 . Sheep — 

Coarse wool 20 1.2 10.5 .2 11.9 9.1 

Fine wool 23 1.5 12. .3 13.8 8.5 

6 . Ewes, sucking lambs 25 2.9 15. .5 18.4 5.6 

6 . Fattening sheep — 

First period 30 3. 15. .5 18.5 5.4 

Second period 28 3.5 14.5 .6 18.6 4.5 

7 . Horses — 

Light work 20 1.5 9.5 .4 11.4 7. 

Moderate work 24 2. 11. .6 13.6 6.2 

Severe work 26 2.5 13.3 .8 16.6 6. 

8 . Brood sows 22 2.5 15.5 .4 18.4 6.6 

9 . Fattening swine — 

First period 36 4.5 25. .7 30.2 5.9 

Second period 32 4. 24. .6 28.5 6.3 

Third period 25 2.7 18. .4 21.1 7. 



10 Growing Cattle 














Dairy Breeds 














Live weight 












Age in 


per head 












months 


Lba. 












2-3. . . 


150 23 


4. 


13. 


2. 


21. 


4.5 


3-6. . . 


300.... 24 


3. 


12.8 


1. 


16.8 


5.1 


6-12.. 


500.... 27 


2. 


12.5 


.5 


15. 


6.8 


12-18. . 


700 26 


1.8 


12.5 


.4 


14.7 


7.5 


18-24. . 


900 26 

Beef Breeds 


1.5 


12. 


.3 


13.8 


8.5 


2-3. . . 


165.... 23 


4.2 


13. 


2. 


19.2 


4.2 


3-6. . 


330 24 


3.5 


12.8 


1.5 


17.8 


4.7 


6-12 


550 25 


2.5 


13.2 


.7 


16.4 


6. 


12-18. 


750 24 


2. 


12.5 


.5 


15. 


6.8 


18-24. 


935.... 24 


1.8 


12. 


.4 


14.2 


7.2 



FEEDING STANDARDS 



459 



Kind of animal 

Growing Sheep 

Wool Breeds 

Live weight 
Age in per iiead 

months Lbs. 

4r-6 60... 

6-8 75... 

8-11 85... 

11-15 90. . . 

15-20 100... 

Mutton Breeds 

4-6 65.. . 

6-8 85... 

8-11 100. .. 

11-15 120... 

15-20 150... 



Per 1,000 Lbs. Live Weight, Daily 

Dry ^-Digestible organic substances— N Nutri- 
sub- Pro- Carbo- tive 

stance tein hydrates Fat Total ratio 1: 
Lbs. Lbs. Lbs. Lbs. Lbs 



.25 


3.4 


15.4 


.7 


19.5 


5. 


.25 


2.8 


13.8 


.6 


17.2 


5.4 


.23 


2.1 


11.5 


.5 


14.1 


6. 


.22 


1.8 


11.2 


.4 


13.4 


7. 


.22 


1.5 


10.8 


.3 


12.6 


7.7 


.26 


4.4 


15.5 


.9 


20.8 


4. 


.26 


3.5 


15. 


.7 


19.2 


4.8 


.24 


3. 


14.3 


.5 


17.8 


5.2 


.23 


2.2 


12.6 


.5 


15.3 


6.3 


.22 


2. 


12. 


.4 


12.4 


6.5 



Growing Swine 
Breeding Stock 

2-3 45. 

3-5 100. 

6-6 120. 

6-8 175. 

8-12 260. 

Growing Fattening Animals 

2-3 45. 

3-5 110. 

5-6 150. 

6-8 200. 

8-12 275. 



...44 


7.6 


28. 


1. 


35.7 


4. 


...35 


5. 


23.1 


.8 


28.9 


5. 


. . .32 


3.7 


21.3 


.4 


25.4 


6. 


. . .28 


2.8 


18.7 


.3 


21.8 


7. 


...25 


2.1 


15.3 


.2 


17.6 


7.5 


...44 


7.6 


28. 


1. 


35.7 


4. 


.. .35 


5. 


23.1 


.8 


28.9 


5. 


. ..33 


4.3 


22.3 


.6 


27.2 


5.5 


...30 


3.6 


20.5 


.4 


24.5 


6. 


...26 


3. 


18.3 


.3 


21.6 


6.4 



460 



APPENDIX 



6. FERTILIZING CONSTITUENTS OJF AMERICAN 

FEEDING-STUFFS 

This table is the one prepared by the OflSce of Ex- 
periment Stations, United States Department of Agricul- 
tm-e, and pubHshed in the Handbook of Experiment 

Station Work, Bulletin No. 15. pj^^^ p^^^^_ 

phoric slum 

Moisture Ash Nitrogen acid oxide 

% % % % % 
Green Fodders 

Com fodder 78.61 4.84 .41 .15 .33 

Sorghum fodder 82.19 . . .23 .09 .23 

Rye fodder 62.11 .. .33 .15 .73 

Oat fodder 83.36 1.31 .49 .13 .38 

Common mUlet 62.58 . . .61 .19 .41 

Japanese millet 71.05 . . .53 .2 .34 

Hungarian grass (German millet) 74.31 . . .39 .16 .55 
Orchard grass {Dactylis glomer- 

ata)* 73.14 2.09 .43 .16 .76 

Timothy grass {Phleum pratense)* 66,9 2.15 .48 .26 .76 
Perennial rye grass {Lolium 

perenne)* 75.2 2.6 .47 .28 1.1 

Italian rye grass {Lolium itali- 

cum)* 74.85 2.84 .54 .29 1.14 

Mixed pasture grasses 63.12 3.27 .91 .23 .75 

Red clover {Trifolium pratense) . . 80. . , .53 .13 .46 

White clover {Trifolium repens) . . 81. . . .56 .2 .24 
Alsike clover {Trifolium hyhri- 

dum) 81.8 1.47 .44 .11 .2 

Scarlet clover {Trifolium incar- 

natum) 82.5 . . .43 .13 .49 

Alfalfa {Medicago saliva) 75.3 2.25 .72 .13 .56 

Cowpea 78.81 1.47 .27 .1 .31 

Serradella {Ornithopis sativus). . . . 82.59 1.82 .41 .14 .42 

Soja bean {Glycine soja) 73.2 . . .29 .15 .53 

Horse bean {Vida faba) 74.71 . . .68 .33 1.37 

White lupine {Lupinus albus) ... . 85.35 . . .44 .35 1.73 

Yellow lupine {Lupinus luteus)* . . 83.15 .96 .51 .11 .15 

Flat pea {Lathyrus sylvestris)* ... . 71.6 1.93 1.13 .18 .58 

Common yetch. {Vicia saliva)* .. . 84.5 1.94 .59 1.19 .7 
Prickly comfrey {Symphytum as- 

perrimum) 84.36 2.45 .42 .11 .75 

Corn silage 77.95 . . .28 .11 .37 

Com and soja-bean silage 71.03 . . .79 .42 .44 

Apple pomace silage* 75. 1.05 .32 .15 .4 

♦Dietrich and Konig: Zusamensetzung und Verdaulichkeit der Futtermittei. 



FERTILIZING CONSTITUENTS 461 



Moisture Ash 

% % 
Hay and Dry Coarse Fodders 

Corn fodder (with ears) 7.85 4.91 

Com stover (without ears) 9.12 3.74 

Teosinte {Euchbena luxurians) . . . 6.06 6.53 

Common millet 9.75 . . 

Japanese millet 10.45 5.8 

Hungarian grass 7.69 6.18 

Hay of mixed grasses 11.99 6.34 

Rowen of mixed grasses 18.52 9.57 

Red-top {Agrostis vulgaris) 7.71 4.59 

Timothy 7.52 4.93 

Orchard grass 8.84 6.42 

Kentucky blue -grass (Poa pra- 

tensis) 10.35 4.16 

Meadow fescue {Festuca pratensis) 8.89 8.08 
Tall meadow oat grass {Arrhena- 

thrum avenaceum) 15.35 4.92 

Meadow foxtail {Alopecurus pra- 
tensis) 15.35 5.24 

Perennial rye grass 9.13 6.79 

Italian rye grass 8.71 . . 

Salt marsh hay 5.36 . . 

Japanese buckwheat 5.72 . . 

Red clover 11.33 6.93 

Mammoth red clover {Trifolium 

medium) 11.41 8.72 

White clover 

Scarlet clover* 18.3 7.7 

Alsike clover 9.94 11.11 

Alfalfa 6.55 7.07 

Blue melilot (Melilotus cseruleus) . 8.22 13.65 

Bokhara clover (Melilotu^ alba) . . 7 A3 7.7 

Sainfoin {Onobrychis sativa) 12.17 7.55 

Sulla (Hedysarum coronarium) . . . 9.39 . . 

LotiLs villosus 11.52 8.23 

Soja bean (whole plant) 6.3 6.47 

Soja bean (straw) 13. 

Cowpea (whole plant) 10.95 8.4 

Serradella 7.39 10.6 

Scotch tares 15.8 . . 

Ox-eye daisy {Chrysanthemum leu- 

canthemum) 9.65 6.37 

Dry carrot tops 9.76 12.52 

Barley straw 11.44 5.3 

Barley chaff 13.08 

♦Dietrich and Konig. 





Phos- 


Potas- 




phoric 


sium 


ritrogen 


acid 


oxide 


% 


% 


% 


1.76 


.54 


.89 


1.04 


.29 


1.4 


1.46 


.55 


3.7 


1.28 


.49 


1.69 


1.11 


.4 


1.22 


1.2 


.35 


1.3 


1.41 


.27 


1.55 


1.61 


.43 


1.49 


1.15 


.36 


1.02 


1.26 


.53 


.9 


1.31 


.41 


1.88 


1.19 


.4 


1.57 


.99 


.4 


2.1 


1.16 


.32 


1.72 


1.54 


.44 


1.99 


1.23 


.56 


1.55 


1.19 


.56 


1.27 


1.18 


.25 


.72 


1.63 


.85 


3.32 


2.07 


.38 


2.2 


2.23 


.55 


1.22 


2.75 


.52 


1.81 


2.05 


.4 


1.31 


2.34 


.67 


2.23 


2.19 


.51 


1.68 


1.92 


.54 


2.8 


1.98 


.56 


1.83 


2.63 


.76 


2.02 


2.46 


.45 


2.09 


2.1 


.59 


1.81 


2.32 


.67 


1.08 


1.75 


.4 


1.32 


1.95 


.52 


1.47 


2.7 


.78 


.65 


2.96 


.82 


3. 


.28 


.44 


1.25 


3.13 


.61 


4.88 


1.31 


.3 


2.09 


1.01 


.27 


.99 



462 



APPENDIX 



Moisture 

% 
Hay and Dry Coarse Fodders — 
continued 

Wheat straw 12.56 

Wheat chaff 8.05 

Rye straw 7.61 

Oat straw 9.09 

Buckwheat hulls 11.9 

Roots, Bulbs, Tubers, etc. 

Potatoes 79.75 

Red beets 87.73 

Yellow fodder beets 90.6 

Sugar-beets 86.95 

Mangel-wurzels 87.29 

Turnips 89.49 

Rutabagas.. 89.13 

Carrots 89.79 

Grains and Other Seeds 

Corn kernels 10.88 

Sorghum seed 14. 

Barley* 14.3 

Oats 18.17 

Wheat (spring) 14.35 

Wheat (winter) 14.75 

Rye 14.9 

Common millet 12.68 

Japanese millet 13.68 

Rice 12.6 

Buckwheat 14.1 

Soja beans 18.33 

Mill Products 

Corn meal 12.95 

Corn-and-cob meal 8.96 

Ground oats 11.17 

Ground barlej' 13.43 

Rye flour 14.2 

Wheat flour 9.83 

Pea meal 8.85 

By-products and Waste Materials 

Corncobs 12.09 

Hominy feed 8.93 

Gluten meal 8.59 

Starch feed (glucose refuse) 8.1 

♦Dietrich and Konig. 







Phos- 


Potas- 






phoric 


sium 


Ash 


Nitrogen 


acid 


oxide 


% 


% 


% 


% 


3.81 


.59 


.12 


.51 


7.18 


.79 


.7 


.42 


3.25 


.46 


.28 


.79 


4.76 


.62 


.2 


1.24 




.49 


.07 


.52 


.99 


.21 


.07 


.29 


1.13 


.24 


.09 


.44 


.95 


.19 


.09 


.46 


1.04 


.22 


.1 


.48 


1.22 


.19 


.09 


.38 


1.01 


.18 


.1 


.39 


1.06 


.19 


.12 


.49 


9.22 


.15 


.09 


.51 


1.53 


1.82 


.7 


.4 


, . 


1.48 


.81 


.42 


2.48 


1.51 


.79 


.48 


2.98 


2.06 


.82 


.62 


1.57 


2.36 


.7 


.39 


. . 


2.36 


.89 


.61 


, , 


1.76 


.82 


.54 


. . 


2.04 


.85 


.36 


, , 


1.73 


.69 


.38 


.82 


1.08 


.18 


.09 


. , 


1.44 


.44 


.21 


4.99 


5.3 


1.87 


1.99 


1.41 


1.58 


.63 


.4 


. , 


1.41 


.57 


.47 


3.37 


1.86 


.77 


.59 


2.06 


1.55 


.66 


.34 


, . 


1.68 


.85 


.65 


1.22 


2.21 


.57 


.54 


2.68 


3.08 


.82 


.99 


.82 


.5 


.06 


.6 


2.21 


1.63 


.98 


.49 


.73 


5.03 


.33 


.05 


, , 


2.62 


.29 


.15 



FERTILIZING CONSTITUENTS 463 



Moisture Ash 
% % 



By-products and Waste MateriaU— 
continued 

Maltsprouts 10.38 12.48 

Brewers' grains (dry) 6.98 6.15 

Brewers' grains (wet) 75.01 . . 

Rye bran 12.5 4.6 

Rye middlings* 12.54 3.52 

Wheat bran 11.74 6.25 

Wheat middlings 9.18 2.3 

Rice bran 10.2 12.94 

Rice polish 10.3 9. 

Buckwheat middlings* 14.7 1.4 

Cottonseed meal 9.9 6.82 

Cottonseed hulls 10.63 2.61 

Linseed meal (old process) 8.88 6.08 

Linseed meal (new process) 7.77 5.37 

Apple pomace 80.5 .27 

♦Dietrich and Konig. 





Phos- 


Potas- 




phoric 


sium 


[itrogen 


I acid 


oxide 


% 


% 


% 


3.55 


1.43 


1.63 


3.05 


1.26 


1.55 


.89 


.31 


.05 


2.32 


2.28 


1.4 


1.84 


1.26 


.81 


2.67 


2.89 


1.61 


2.63 


.95 


.63 


.71 


.29 


.24 


1.97 


2.67 


.71 


1.38 


.68 


.34 


6.64 


2.68 


1.79 


.75 


.18 


1.08 


5.43 


1.66 


1.37 


5.78 


1.83 


1.39 


.23 


.02 


.13 



INDEX 



Abomasum, the, 103. 
Absorption of food, 116, 
Accessories, food, 193. 
Acids, the, 80. 
fatty, 84. 
amino, 66. 

limiting factor, 191. 
Age, influence of, 133. 

relation to meat production, 428. 
Air, carbon in, 13. 
Albuminoids, 57. 
Alimentary canal, parts of, 94. 
Alfalfa, 227. 
Amides, 66. 
Amylopsin, 109. 
Animal, ash elements, 23. 

bodies, mineral compounds of, 

44. 
fats, food sources, 208. 
foods, origin of, 9, 266. 
growth, chemical elements in, 

12. 
heat, a waste product, 184. 
regulation of, 183. 
source of, 10. 
organism, work performed by, 

162. 
production, adaptability of 

crops to, 273. 
refuses, 270. 

size of in relation to ration, 301. 
substance, source of, 10. 
Animals, cruelty to, 433. 
elements in, 21. 
environment and treatment, 

431. 
factors in management of, 425. 
fattening, experiments with, 
365. 
feeding experiments in, 366. 
food needs of, 364. 



Animals, fattening, rate of increase, 
363. 
selection for meat production, 

427. 
young, milk for, 351. 
Anti-bodies, 85. 
Argon, 17. 

Ash compounds, distribution in 
the animal body, 45. 
distribution in parts of plants, 

42. 
in plants, 39. 
constituents, influence of manu- 
facturing processes, 43. 
for egg production, 409. 
elements in, 21. 
after ignition, 39. 
in blood, 46. 

elements in soft tissues, 46. 
of plants, mineral compounds 

in, 38. 
variation in plants, 40. 
variations due to species, 40. 
Assimilation, 87. 

Bacteria, 89. 

intestinal, 110. 

in digestive tract, 92. 
Barley feed, 250. 

Beef, growth in production of, 363. 
Beet, sugar-, molasses, 256. 

residues from, 255. 
Beri-beri, 193. 
Bile, the, 106. 

function of, 107. 
Birds, digestive apparatus of, 403. 

food needs of, 399. 

young, rations for, 413. 
Blood, the, 138. 

ash elements in, 46. 

circulation of, 142. 



DD 



(465) 



466 



INDEX 



Blood corpuscles, 139. 

the plasma, 140. 

vessels, in absorption, 115. 
Bovines, maintenance rations for, 

314. 
Breakfast foods, residues from, 

248. 
Breed, influence of, 133. 
Brewers' grains, 251. 
Buttermilk, 268. 

Calcium, 19. 

Calorie, definition of, 165. 
Calorimeter, respiration, 214. 
Carbohydrates, the, 69. 

as a source of fats, 161. 

classification of, 70. 

digestibility of, 120. 

functions of, 160. 

physiologically economical, 186. 

regulation of use, 149. 

source of energy, 160. 
Carbon, 13. 

dioxide, elimination of, 147. 
Cattle foods, classification of, 219. 
distinctions in, 263. 
energy values of, 166. 
Cellulose, 78. 

and gums, digestibility of, 121. 
Chlorine, 18. 

Coarse foods vs. grains, 263. 
Collagen, 57. 
Colts, feeding, 358. 

rations for, 359. 
Cooking foods, 128. 
Combination of nutrients, influ- 
ence of, 131. 
Compounds, classes of, 26. 

classification of, 27. 
Combustible and incombustible 

matter, 24. 
Combustion, 24. 
Corn, as silo crop, 231. 
Cottonseed by-products, composi- 
tion of, 259. 

huUs, 257. 

kernels, 258. 

meal, 257. 
Cow, the general purpose, 427. 



Cows, dairy, calculation of rations. 
333. 
feeding standards for, 327. 
practical rations for, 335. 
requirements of, 331. 
selection of, 426. 
Crops, adaptability to environ- 
ment, 272. 
to kind of production, 273. 
drj-ing of, 220. 
ensiling vs. field curing, 233. 
forage, classes of, 220. 
harvesting of, 222. 
influence of maturity, 223. 
for swine, 386. 
high productivity, 275. 
methods of preserving, 233. 
productive capacity of, 274. 
soiling, 276. 

value not proportional to yield, 
224. 
Curing fodders, losses through, 
221. 

Dairy by-products, 268. 

wastes, as food for pigs, 384. 
Dextrin, 78. 
Dextrose, 71. 
Digestible nutrients, in the ration, 

299. 
Digestibility, as basis of values, 
286. 

determination of, 135. 

influence of age, 225. 

meaning of, 122. 
Digestion, 87. 

artificial, 103. 

as a whole, 112. 

changes in food, 88. 

changes in stomach, 104. 

coefl&cients, inaccuracies of, 136. 

factors influencing, 122. 

in intestines, 113. 

stimuli to, 111. 

stomach, 112. 

summary of changes, 114. 

work of, 176. 
Digestive fluids, 113. 
Di-saccharides, 72. 



INDEX 



467 



Drying crops, conditions of, 220. 
Drying fodders, effect of, 125, 221. 

Eggs, composition of, 407. 

Egg production, ash constituents 

for, 409. 
Elements, distribution of, 27. 
Energy, chief source of, 183. 
determination of 165. 

metabolizable, 168. 
distribution of losses of, 169. 
expended in feed consumption, 

177. 
how originated, 163. 
in cattle foods, 166. 
loss from food, 167. 
loss in gases, 168. 
maintenance, distribution of, 

312. 
measurement of, 165. 
metabolizable, 167. 
estimates of, 171. 
in feeding-stuffs, 172. 
in fodders and grains, 173. 
nature of, 163. 
net, 174. 

calculation of, 178. 
necessary to work, 163. 
uses of, 151. 

requirements by growing ani- 
mals, 349. 
stored by plants, 10. 
transformation of, 164. 
values, as basis of valuation, 285. 
calculation of, 212. 
net, computation of, 179. 
determination of, 211. 
with different rations, 175. 
Enzyms, 85. 
action of, 92. 
in pancreatic juice, 108. 
Ether-extracts, 84. 
Esophageal groove, 99. 
Ewes, feeding of, 354. 
Extractives, 67. 

Fat, milk-, 83. 
Fats and oils, 80. 

functions of, 161. 



Fats, digestibility of, 121. 
from carbohydrates, 161. 
in grains and seeds, 81. 
milk-, food sources of, 321. 
nature and kinds of, 82. 
Fat soluble A, 194. 
Fattening animals, rate of increase, 

363. 
Fatty acids, 84. 
Feces, constituents of, 118. 
Feeding and watering, influence of 
frequency, 130. 
experiments as basis of feed 
value, 290. 
conclusions from, 203. 
with fattening animals, 366. 
practical, 203. 
practice, conclusions from, 202. 
standards, 294. 
American, 329. 
Grouven's, 327. 
Kuhn's, 328. 

the Wolff-Lehmann, 328. 
Wolff's, 328. 
Woll's, 329. 
stuffs, classification of, 265. 
commercial by-product, 242. 
commercial values of, 282. 
home supply of, 304. 
misleading terms for, 264. 
physiological values of, 284. 
selection of, 286. 
valuation of, 281. 
valuation by method of least 
squares, 283. 
Feeds, classification of, 264. 

digestibility of various, 287. 
Fermentation, intestinal, 110. 

results of, 91. 
Ferments, 88. 
action of, 91. 
conditions of growth, 80. 
definition of,, 89. 
organized, 89 

structure and distribution of, 89 
unorganized, 92. 
Fertility and legumes, 270. 
Fibrinogen, 55. 
Fibroin, 57. 



468 



INDEX 



Fodders, effect of drj-ing, 221. 

losses through curing, 221. 

preserving of, 126. 
Food, absorption of, 114, 116. 

appropriation by growing ani- 
mals, 347. 

as a source of energ>', 162. 

combustion, measxrrement of, 
213. 

compounds, inter-relation of, 
185. 
relation to the digestive pro- 
cesses, 119. 

economics, factors involved in, 
420. 

effect on constitution of milk 
solids, 340. 

effect on the flavors of milk, 
343. 

effect on the proportion of milk 
solids, 339. 

general uses of, 151. 

influence on kind of growth, 
347. 

maximum absorption of, 117. 

needs of fattening sheep, 373. 

relation to quality of the horse, 
357. 

relation to production, 420. 

requirements for pork produc- 
tion, 381. 

unit, the, 418. 

use of, 145. 

wetting, 128. 
Foods, animal, origin of, 266. 

cooking, 128. 

influence of grinding, 129. 

influence on milk-fats, 341. 

kinds for poultry, 400. 
Forage crops, classes of, 220. 
harvesting of, 222. 
yield at maturity, 223. 
Fowls, adaptability of various 
foods to, 415. 

feeding standards for, 411. 

maintenance ration for, 412. 

salt a necessity for, 410. 

supply of grit, 410. 



Galactose, 71. 

Gastric juice, the, 103. 

Gelatin, 57. 

Gelatinoids, nutritive value of, 

192. 
Gliadin, 56 
Globulins, 53. 

animal, 55. 

plant, 54. 

serum, 56. 
Glucose, 93. 
Glutenins, 56. 
Gluten products, 252. 
Glycogen, 77. 
Glyco-proteins, 59. 
Grain, storage of, 241. 
Grains and seeds, 240. 

coarse food, 263. 
Green versus dried fodders, 220. 
Grinding foods, influence of, 129. 
Grit, supply for fowls, 410. 
Growing animals, energy require- 
ments of, 349. 
Growth, effect on water-content, 
32. 

in beef production, 363. 

in fattening sheep, 372. 

influence of food upon, 347. 

requirements for, 346. 
Growth-promoting bodies, 303. 
Gums, the, nutritive value of, 188. 

Hay values, Thaer's, 327. 
Heart, the, 140. 
Hsematin, 60. 
Hemi-celluloses, 77. 
Haemoglobin, 60. 

Hen, constituents of the body, 406. 
Hens, lajdng, effects of food upon, 
402. 
rations for, 412. 
Histones, 58. 
Hominy feed, 251. 
Hordein, 56. 
Hormones, 85. 
Horse, the, a machine, 164, 387. 

estimate of work ration, 392. 

food requirements, 390. 

maintenance needs of, 315. 



INDEX 



469 



Horse, relation of food to quality, 
357. 
the stomach of, 104. 
work performed by, 388. 
Horses, digestibility of coarse 
foods by, 134. 
maintenance food for, 315. 

rations for, 317. 
oats as food, 396. 
working, nutritive ratio for, 395. 
rations for, 397. 
source of the ration, 394. 
Hydrochloric acid in stomach 

digestion, 104. 
Hydrogen, 15. 
Hydrolysis, 72, 93. 

Individuality, influence of, 133. 

influence on energy losses, 171. 
Intestinal juices, 109. 
action of, 113. 

tract, changes in the walls of, 
116. 
Intestines, the, 105. 

form and length of, 105. 
Invertase, 93. 
Iodine, 19. 
Iron, 19. 



Katabolism, fasting, 311. 

Keratins, 57. 

Knowledge, sources of, 201 

\ 
Lactase, 93. 
Lactose, 73. 

Lacteals, function of, 115. 
Lambs, feeding of, 354. 

grain food for, 355. 
Lecithins, 85. 
Lecitho-proteins, 60. 
Legumes and fertility, 276. 
Levulose, 71. 
Linseed meal, 259. 

oil, extraction of, 260. 
Liver, the, 149. 
Lungs, the, 143. 
LjTiiphatic system, 115. 



Maintenance food for horses, 315. 
for sheep, 317. 
measured by fasting katabolism, 

311. 
needs, computation of, 313. 
investigations concerning, 309. 

of the horse, 315. 
rations for bo vines, 314. 
for fowls, 412. 
Maize, 226. 

kernel, the, structure of, 252. 
Maltsprouts, 251. 
Maltase, 93. 
Maltose, 73. 

Manufacturing processes, influ- 
ence on ash, 43. 
Man's relation to animal life, 3. 
Mastication, 94. 
work of, 174. 
Matter, classes of, 23. 
Meat production, relation of age 
to, 428. 
selection of animals for, 427. 
Metabolism, fasting, use of nu- 
trients in, 312. 
Meta-proteins, 61. 
Methane, losses through, 171. 
Mflk, 266. 

cows', composition of, 319. 
effect of food upon flavors, 343. 
fats, food sources of, 321. 
fats in, 83. 

influence of food upon, 341. 
for young animals, 351. 
of several breeds, 268. 
production, protein require- 
ments for, 325. 
production, use of nutrients in, 

323. 
proteins, food sources of, 321. 
relation to food, 338. 
secretion of, 320. 
solids, effect of food upon con- 
stitution of, 340. 
effect of food upon propor- 
tions, 339. 
rate of formation of, 322. 
substitutes for calves, 354. 
substitutes for swine, 385. 



470 



INDEX 



Milling processes, 247. 
Mineral compounds, in animal 
bodies, 44. 
in ash of plants, 38. 
elements, distribution of in ani- 
mal body, 154. 
equilibrium of in animal body, 

154. 
functions of, 152. 
relation to animal structure, 

153. 
relation to tissue develop- 
ment, 155. 
relation to elimination of 

waste products, 154. 
relation to muscular control, 

155. 
relation to osmosis, 155. 
relation to vital processes, 

152. 
supply of, 156. 
Mono-saccharides, 70. 
Motive power, source of, 11. 
Mouth, the, 94. 

Muscular activity, relation to pro- 
tein, 183. 
control, relation to mineral ele- 
ments, 155. 
Mutton production, 371. 
Myosin, 55. 
Myosinogen, 55. 

New process linseed meal, 260. 
Nitrogen, 16. 

compounds, relative impor- 
tance of, 189. 
supply of, 16. 
uses of, 17. 
Non-nitrogenous compounds, 
classification of, 69. 
composition of, 68. 
Non-proteins, 66. 
Nucleo-proteins, 58. 
Nutrients, digestible, calculation 
of, 297. 
energy value of, 212. 
energy values, 166. 
functions of, 151. 
how oxidized, 145. 



Nutrients, quantity for fattening 
sheep, 374. 

rate of oxidation, 146. 

use in fasting metabolism, 312. 

uses in milk production, 323. 
Nutrition, laws of, 197. 
Nutritive ratio, 295. 

Oat clippings, 250. 

grain, the, 249. 

hulls, 248. 
Oats, as horse feed, 359. 

for working horses, 396. 
Oil meal, 259. 

meals, the, 256. 
Oils, methods of extracting, 257. 
Old process linseed meal, 260. 
Omasum, the, 102. 
Organic and inorganic matter, 25. 
Osmosis, relation to mineral ele- 
ments, 155. 
Oxidases, 146. 
Oxygen, 14. 

uses of, 15. 
Oxy-haemoglobin, 60. 

Palatableness, 292. 
Pancreatic juice, the, 123, 108. 

enzyms of, 108. 
Pectin bodies, the, 78. 
Pellagra, 195. 
Pentosans, the, 77. 
Pentoses, the, 72. 
Peptones, the, 62. 
Pepsin, 104. 

in gastric juice, 104. 
Phospho-proteins, 59. 
Phosphorus, 18. 

compounds, relative efficiency 
of, 157. 
Physiological requirements, 294. 
Pig, stomach of, 104. 
Pigs, dairy wastes for, 384. 

unwise feeding, 382. 
Plant ash, elements in, 21. 
Plans, elements in, 20. 

new versus old species, 273. 
Plasma, of blood, 140. 
Poly-saccharides, 74. 



INDEX 



471 



Pork production, 378. 

food requirements for, 381. 
Potassium, 19. 

Poultry, kinds of food for, 400. 
Preparation of food, influence of 

methods, 127. 
Preserving fodders, influence of 
conditions and methods, 
126. 
Problems in feeding animals, 5. 
Production, relation to food, 420. 
the unit of, 419. 
values, estimation of, 181. 
relation to profit, 195. 
Proteans, 61. 

Protein as a source of energy, 159. 
of fats, 159. 
coagulated, 61. 
commercial, 336. 
content as basis of valuation, 

289. 
derivatives, 60. 
efficiency from animal sources, 

408. 
foods, no single one essential, 

337. 
functions of, 158. 
home supply of, 276, 336. 
how determined, 48. 
importance of, 47. 
physiologically necessarj', 186. 
relation to muscular activity, 

183. 
relative importance overstated, 

326. 
requirements for milk-produc- 
tion, 325. 
sparers, 187. 

standards, revision of, 303. 
supply of, 302. 
Proteins, alcohol soluble, 56. 
as tissue formers, 158. 
classification of, 49. 
cleavage products of, 63. 
digestibility of, 119. 
efficiency of, 215. 
familiar examples of, 52. 
greatly unlike, 49. 
glyco-, 59. 



Proteins, lecitho-, 60. 

milk, food sources of, 321. 

not wholly oxidized, 146. 

nucleo-, 58. 

phospho-, 59. 

phosphorus-bearing synthesis 
of, 192. 

properties of, 62. 

simple, 52. 

the true, 50. 

relative efficiency of, 190. 

ultimate composition of, 51. 

unlike constitution of, 63. 
Proteoses, 62. 
Psychic factor, the. 111. 
Ptyalin, 98. 

Ration, calculating of, 296. 

influence on development of 
swine, 383. 
and quantity of, 124. 
of size of, 171. 
on quality of product, 304. 
insufficient, correcting of, 300. 
maintenance, 307. 
character of, 307. 
for bovines, 309. 
for horses, 317. 
how provided, 308. 
proportion used as fuel, 160. 
the manipulation of, 429. 
the quantity of, 431. 
relation to size of animal, 301. 
selection of, 305. 
uses of production, 308. 
Rations, adaptation of, 293. 

calculations for dairy cows, 333. 
fattening, selection of, 369. 
for laying hens, 412. 
for young birds, 413. 
practical, for dairy cows, 335. 
selection of, for sheep, 376. 
Rennin, in stomach, 104. 
Respiration, 143. 
apparatus, 209. 
calorimeter, 214. 
object of, 144. 
Reticulum, the, 101. 
Rigor mortis, 55. 



472 



INDEX 



Roots and tubers, 239. 
Rumen, the, 100. 
Rumination, 102. 

Saccharose, 72. 

Saliva, the, 97. 

origin of, 97. 

properties and office of, 97. 
quantity excreted, 98. 
Salt, effect of, 129. 

a necessity for fowls, 410. 
Sap, 31. 
Season and storage, influence of, 

131. 
Screenings, 247. 
Secretins, 85, 111. 
Sheep, fattening, food needs of, 
373. 
quantity of nutrients for, 

374. 
nature of growth, 372. 
growing, standards for, 356. 
maintenance food for, 317. 
place on the farm, 371. 
selection of rations for, 376. 
Silage, acidity of, 230. 

cutting and shredding, 237. 
crops for, 234. 
growth of com for, 236. 
Silo, changes in, 228. 

cleavage of proteins in, 230. 
extent of loss in, 231. 
filling the, 236. 
importance of losses in, 233. 
losses in, 229. 
necessary loss in, 232. 
rate of filling, 237. 
Silos, construction of, 235. 
Skimmed milk, 268. 
for calves, 351. 
Sodium, 19. 

Soft tissues, ash elements in, 46. 
Soiling, conditions favorable to, 
277. 
crops a necessity, 276. 
area and rotation, 280. 
selection of, 278. 
the economy of, 277. 
Soil moisture, influence of, .33. 



Species, influence of, 133. 

Spongin, 57. 

Stage of growth, influence of. 

127. 
Standards, German, for fattening 
animals, 367. 

for milk production, 330. 
Starch, manufacture of, 253. 
Starches, the, 75. 

rate of digestibility, 120. 
Steapsin, 108. 
Steers, fattening, rations for, 

370. 
Stomach, the, 99. 
Straws, the, 239. 
Sugar-beet pulp, 255. 
Sugars, the, 74. 

simple, 70. 
Swine, changes in production, 
379. 

character of the growth, 379. 

feeding of, 378. 

forage crops for, 386. 

influence of ration on develop- 
ment, 383. 

Teeth, the, 95. 

Temperature, the critical, 185. 

regulation of, 183. 
Therm, definition of, 165. 

Urea, elimination of, 147. 

Vitamines, 85, 193. 
Vitellin, 56. 

Wastes, elimination of, 146. 
Water, 28. 

content, conditions affecting, 34. 
measurement of, 29. 
variation in animal bodies, 
37. 
elimination of, 147. 
functions of, 152. 
hygroscopic, 29. 
in feeding-stuffs, 34. 
in li\dng plants, 30. 
in the animal, 36. 
physiological, 30. 



INDEX 



473 



Water, proportion in plants, 31. 
relation to preservation of foods, 
35. 
Water soluble B, 194. 
Water-supply, for fowls, neces- 
sity of, 408. 
to plants, 33. 
Wheat, composition of milling 
products, 246. 



Wheat, grain, structure of, 243. 

offals, 243. 

the milling of, 245. 
Whey, 268. 
Work, food expenditure for, 389. 

influence of, 133. 

of animal organism, 162. 

Zein, 56. 



i 



The following pages contain advertisements of a 
few of the Macmillan books on kindred subjects 



-s_ ^ 



The Breeds of Live Stock 

By Live Stock Breeders. Revised and arranged by CARL 
W. GAY, Professor of Animal Husbandry in the University 
of Pennsylvania. 



RURAL TEXT.BOOK SERIES 

Illustrated, 8vo, $1.75 

A more urgent demand, from a constantly increasing nimiber of 
consumers, for animal products must stimulate a greater exploitation 
of pure-bred live stock as the source of the seed from which market 
animals and their products are derived. The breeders who wiU 
get the most out of the respective breeds with which they work will 
be those best informed as to the inherent possibiHties of their stock. 
Study of the origin, history and development of the breeds is, there- 
fore, important. The most successful breeders are essentially spe- 
ciaUsts, and the most authoritative presentation of the historic facts, 
points of merit and economic importance of the different breeds 
should be expected from those who have devoted themselves most 
exclusively to these breeds. 

Men who have been more or less eminently identified with the 
respective breeds were chosen to prepare the breed material for the 
Cyclopedia of American Agriculture. This matter has been revised, 
brought up to date and amplified to include types in their relation 
to breeds, and the whole material has been edited, arranged and 
revised by Dr. Carl W. Gay, Professor of An'mal Husbandry in the 
School of Veterinary Medicine of the University of Pennsylvania. 
The original illustrations are reproduced in half-tones, and the book 
is offered as the most complete and recent work on the types and 
breeds of livestock. 



THE MACMILLAN COMPANY 

PUBLISHERS 64-66 Fifth Avenue NEW YORK 



The Principles and Practice of 
Live-Stock Judging 

By carl warren GAY 

Professor of Animal Industry in the 
University of Pennsylvania 

Rural Textbook Series. Cloth, ismo^ illustrated, $1.30 

This book has been prepared to meet the demand incident to the 
progress made in livestock husbandry for a more comprehensive, 
thorough, and systematic study of the judging of animals. The 
effort has been made in its preparation to take the student and 
stockman a step further than they have gone heretofore. Part I 
introduces the principles upon which the practice of judging is 
founded ; Part II applies to the practice of judging, definition and 
procedure — the features of animal form to be considered, the means 
of making observations and practice judging by the score card, 
demonstrations, comparative and competitive judging. The bal- 
ance of the work is devoted to special judging, one part being given 
to each of the following : horses, cattle, sheep, swine, the judging 
of breeding animals, and livestock shows. The volume is profusely 
illustrated, typical representatives of the types and breeds being 
shown in untouched photographs of animals to which championship 
honors have been awarded. 



THE MACMILLAN COMPANY 

Publishers 64-66 Fifth Avenue New Tork 



THE SCIENTIFIC FEEDING 
OF ANIMALS 

By Professor O. KELLNER 

( 

Authorized Translation by WILLIAM GOODWIN, B.Sc, 
Ph.D., Lecturer on Agricultural Chemistry, and Head of the Chem- 
ical Department, South-Eastern Agricultural College (University 
of London), Wye, Kent. 

New Edition. Cloth, 12mo, $1.75 

An authorized English translation of the valuable work of Dr. 
O. Kellner. It explains in simple language the general laws which 
underlie the feeding of animals and the scientific foundations upon 
which the principles of animal nutrition rest. 

"I wish to say that it is one of the most valuable books in the 
English language on Feeding Farm Animals. The author is extremely 
lucid in expression and concise in statement. He covers his field in 
a manner that is well planned and such as will give the reader a 
most excellent knowledge of the general principles of Feeding." — 
Professor Charles S. Plumb, Ohio State University. 

"Dr. KeUner's standing as a student and investigator in this 
subject is too high for any words of commendation to be needed, and 
I feel sure that the translator and publisher have done a service in 
rendering this work available to English and American students."— 
Professor Henry P. Armsby, Pennsylvania State College. 



THE MACMILLAN COMPANY 

PUBLISHERS 64-66 Fifth Avenue NEW YORK 



Animal Husbandry for 
Schools 

By MERRITT W. HARPER 

Cloth, 12mo, illustrated, 409 pp., SI.40 
RURAL TEXT-BOOK SERIES 

With the increasing study of agricultural subjects in the schools 
has come a demand for a book on Animal Husbandry suitable for 
use by students of high school age. It is to meet such a need that 
this book has been written, and in content, style, and arrangement 
it is admirably adapted to the purpose. It belongs to the Rural 
Textbook Series prepared under the editorial supervision of 
Professor L. H. Bailey, of Cornell University. 

In the five parts into which the book is divided the author treats 
horses, cattle, sheep, swine, and poultry, and each is discussed with 
reference to breeds, judging the animal, feeding, and care and 
management. There is also a chapter on the general principles of 
feeding. Practical questions and numerous laboratory exercises 
supplement the text and compel the student to think through each 
subject as he proceeds. The book is extensively illustrated. Designed 
for use as a textbook, it is also well suited for use as a reference 
book in schools in which time limitations make it impossible to 
use it as a text. 

Manual of Farm Animals 

A Practical Guide to the Choosing, Breeding, and Keep of 
Horses, Cattle, Sheep, and Swine 

By MERRITT W. HARPER, Assistant Professor of Animal Husbandry 
in the New York State College of Agriculture at Cornell University 

Illustrated, decorated cloth, 12mo, S4S pages, index, $2.00 
RURAL MANUAL SERIES 

"The work is invaluable as a practical guide in raising farm 
animals." — Morning Telegram. 

"A book deserving of close study as well as being handy for 
reference and should be in the possession of every farmer interested 
in stock." — Rural World. 

THE MACMILLAN COMPANY 

PUBUSHERS 64-66 Fifth Avtnue NEW YORK 



LIBRARY OF CONGRESS 



000 894 184 1 



